Don't believe blindly what you see on internet. Hinduism or सनातन धर्म (Sanātana Dharma) can't be false as name itself says it is eternal and has "Dharma" in it. Hinduism is confusing for some people because they don't read scriptures in Sanskrit or in other language with proper interpretations of Guru or Acharyas.
To understand Hinduism properly, first you should have some knowledge about Sanskrit Language or Veda Bhasha. Sanskrit is language of Attributes. It doesn't have proper nouns. Krishna is named for person who is "black". Shiva is named for a person who is "auspicious". But a person has many attributes. You can call a person by any of his attributes. But Lord or Parabrahma has infinite attributes. So, Parabrahma has infinte names. Unlike other languages, a Sanskrit name gives some info or qualities a person possess. So, if you come across a name "Shiva" in scripture, you should understand that person has an attribute "auspiciousness" besides other additional attributes.
Sanskrit has fixed Dhatus (Verb roots), by which you can analyze the meaning of word by yourself without help of any dictionary. You can even guess Sanskrit word for modern English words. For example, we can derive Sanskrit words for upload and download. Quoting from blog by Gurudev:
Edit: Since many readers asked about giving a practical example of
creating new words in Sanskrit by giving one for Download, have
updated the article with one for download and upload. The attribute of
descending or fetching is Avataara in Sanskrit, so one word for
Download in Sanskrit could be Avataarayati or the act of fetching.
Avaroha represents the attribute of going down, so Download can also
be Avarohayati
Similarly for Upload we can call it Urdhvayati where Urdhva is an
attribute representing upwards in Sanskrit. Aaroha also represents the
attribute of ascent or going up and hence Upload can also be called
Aarohayati
Not only these, you can create any number of words for upload and
download in Sanskrit using the attributes representing upward or
ascent, and downward, fetching or descent. For instance consider the
terms Unnati and Avanati, which represent progress and downfall
respectively. Take the Sanskrit attribute which can represent File,
Patrika. So File uploading and File downloading could be Patrikonnati
and Patrikavanati respectively! The options are limitless!
My intention is not to boast Sanskrit language, but to affirm that Sanskrit language is eternal and so the language of Vedas (Veda Bhasha). Sanskrit has no need to evolve in vocabulary like other languages, though there may be changes in grammar.
Many people have common attributes. An attribute can refer to multiple persons. Meaning of words in a Sanskrit sentence depends on context. Some foreign authors who translated our scriptures failed to derive meaning based on context and rather they translated literal meaning. Quoting from the same blog:
Take for instance the translations making round about people eating
beef or killing the cow during the vedic period. The whole basis of
this myth is translations of Sanskrit verses like the one which
actually means “control your sense organs” which was translated as
“kill the cow“, all just because the word used was go/gau can refer
not only to cow, but also to sense organs in Sanskrit. So when taken
out of context and translated using its most popular object, you end
up with misinterpretations like these. Sanskrit translation can never
be done by going word by word, the entire context should be used as
the basis to understand the meaning. And there are multiple rules and
hints to understand the context of words which we shall learn in the
future lessons of this series
You can read introduction lessons to Sanskrit by Gurudev, where author explains beautifully about Sanskrit language. Nothing can replace reading our Hindu Scriptures in Sanskrit. Root problem for misinterpretations is lack of Sanskrit Knowledge.
It is also believed Vedas are source of all languages. Refer this question to know more details.
Vedas are eternal scriptures and they are valid for all times. It doesn't matter which yuga you live or which epoch (Kalpa) you live or in which Loka you dwell. Vedas are infallible truths where each and everything can be verifiable. This is what Sri Swami Prabhavanada says in the book Spiritual heritage of India,
The authority of the Vedas does not depend upon anything external.
They themselves are authority, being the knowledge of God. And, as we
shall see later, their truth is verifiable by any spiritual aspirant
in transcendental consciousness.
The Rishis who have gone into deep Tapsya heard them (in transcendental consciousness) . We may not understand them properly and verify all their contents by our limited consciousness. Thus, we need to study them under a knowledgeable Guru (preceptor).
Now coming to your question, you main question is about idol worship. No scripture explicitly rejects idol worship, including Vedas. Indeed, they are not just idols. They have prana in them. We invite Lord or Consciousness into them with Mantras. This process is called Prana Pratishta. Those who condemn idol worship are just half baked Jivas. However, we don't need to invite Lord into Swayambhu (self manifested) murtis, such as Tirupati Venkateswara and Jyotirlingas of Shiva.
Do Vedas and Gita reject idol worship?
This question is already answered here and here . Quoting some verses from the above mentioned answers.
dve vāva brahmaṇo rūpe, mūrtaṃ caivāmūrtaṃ ca [Brh. Up - 2.3.1]
- God (Brahman) has two modes, formless (nirakara, asambhuta) as well as form (sakar, sambhuta).
So, Lord is both Sakara (with form) and Nirakara (without form). You can worship Lord in Sakara or mediatate on Him in Nirakara. Indeed, Lord is everything.
He is also Saguna (with attributes) and Nirguna (without attributes).
Yajurveda Sloka 40.9 you mentioned in the question refers to verse 9 of chapter 40 in Vajasaneyi Samhita of Shukla Yajurveda. Vajasaneyi Samhita is available now only in two recensions, "Kanva" and "Madhyandina", since many recensions are lost due to various historical reasons. This chapter 40 of Vajasaneyi Samhita is also called as Isha Upanishad.
Above Sanskrit verse 40.9 is from Madhandiya recension.
अन्धं तमः प्रविशन्ति ये ऽसम्भूतिम् उपासते
ततो भूय इव ते तमो य उ
सम्भूत्याम् रताः
andhaṁ tamaḥ praviśanti ye 'sambhūtim upāsate
tato bhūya iva te
tamo ya u sambhūtyām ratāḥ
Kanva recension of same 40.9 is
अन्धं तमः प्रविशन्ति ये ऽविद्याम् उपासते
ततो भूय इव ते तमो य उ
विद्यायाम् रताः
andhaṁ tamaḥ praviśanti ye 'vidyām upāsate
tato bhūya iva te tamo
ya u vidyāyām ratāḥ
Same verse with "Sambhutim" is present in 40.12 of Kanva and same verse with "Vidyam" is present in 40.12 of Madhandiya. Only order of verses are changed in different recensions. Let us analyze these two verses.
Verse with "Vidya" is easy to understand.
andhaṁ tamaḥ praviśanti ye 'vidyām upāsate
tato bhūya iva te tamo
ya u vidyāyām ratāḥ
They who worship Avidya alone fall into blind darkness ; and they who
worship Vidya alone fall into even greater darkness. (or)
Into blinding darkness pass they who adhere to karma and into still
greater darkness, as it were, they who delight in meditation.
Adi Shankara says
Now follows a statement of the distinction between the respective
fruits of meditation and karma, as an argument for their simultaneous
practice. Otherwise, if of the two thus proximately stated, one only
is known to bear fruit and not the other, the relation between them
would be (according to rules of interpretation, not one of
co-ordination but) only that of subordination.
Refer introduction section of the this page to know summary of first 8 verses. This verse says both Meditation and karma are important. Indeed, verses 9 to 18 give emphasis for both Karma and Upāsanā.
Now, verse 12 says
andhaṃ tamaḥ praviśanti ye'sambhūtim upāsate |
tato bhūya iva te tamo
ya u sambhūtyāṃ ratāḥ || 12 ||
Into blinding darkness pass they who are devoted to the unmanifest, and into still greater darkness, as it were, they who
delight in the manifest
As we know the context of verses, we can properly understand verses. Adishankara says
Saṃbhavanam means birth. That which is born and is an effect is
sambhūti. asambhūti is [Page 23] what is other than sambhūti i.e.,
prakṛti, the undifferentiated cause whose essence is nescience and
which is the source of all activity and desire. They who devote
themselves to such Cause enter (as may be expected) darkness which is
correspondingly blind in its nature. Sambhūtyām i.e., in the
phenomenal Brahman known as Hiraṇyagarbha. They who delight only in
Him enter darkness which is, as it were, more blinding still.
Griffith also uses the words "Sambhuti" and "Asambhuti" in his translation. So, Sambhuti and Asambhuti are manifested and unmanifested and this verse says one must worship both states of Supreme Brahman.
You can also see Vaishnava interpretation of above verse here.
The translation in your question says it is bad to "worship natural things". But on the other hand, we see divinity in everything. This divinity can be explained with simple logic as said by Swami Krishnananda in his book "lessons on upanishads". I don't quote it here as this will make answer very lengthy.
Verse 32.3 from Vajasaneyi Samhita of Shukla Yajurveda with translation of Griffith
ná tásya pratimā́ asti yásya nā́ma mahád yáśaḥ \
hiraṇyagarbʰá
íty eṣáḥ \
mā́ mā him̐sīd íty eṣā́ \
yásmān ná jātá íty
eṣá \
3.There is no counterpart of him whose glory verily is great. In the
beginning rose Hiranyagarbha, etc. Let not him harm me, etc. Than whom
there is no other born, etc.
This verse describes formless and unmanifested aspect. As we know, Brahman is manifested and unmanifested and at the same time He has form and He is formless.
Some people just misinterpret or give too much emphasis for certain words.
Krishna Paramatma never explicitly rejected idol worship in Bhagavad Gita. I think translations you come across were given by some Hindu haters or by haters of idol worship (to uphold their own Religion).
Lord says the following in Bhagavdgita 7.20 (translated by A Mahadeva Sastri),
bahūnāḿ janmanām ante
jñānavān māḿ prapadyate
vāsudevaḥ
sarvam iti
sa mahātmā su-durlabhaḥ
20.Those whose wisdom has been led away by this or that desire resort to other Gods (Devatas), engaged in this or that rite, constrained by
their own nature.
Adishankara commentary says
Their desires for progeny, cattle, svarga and the like deprive them of
their power of discrimination, and they resort to other Gods
(Devatas), other than Vasudeva, the Self. They engage in rites
peculiar to the worship of these Gods ; they being constrained to do
so by their own nature (prakriti), by that peculiar tendency
(samskara) which they acquired in the previous births.
1. Doesn't it look like the Vedas and the Bhagavata Purana are opposing each other? Why do different Hindu scriptures look like they're opposing each other?
No. Vedas never explicitly support or reject idol worship but on the other hand Puranas extol idol worship. Indeed, we are worshipping Lord inside the idol not idol itself.
2. Will we never know the true meaning of "God is formless, as well as with form" written in the Vedas in this life?
Brihadaranyaka Upanishad 2.3.1 (translated by Swami Madhavananda) says
ढे वाघ ब्रह्मणो रूपे-मूर्त चैवामूर्त च, मत्र्य चामृत च, स्थितं च यच्च,
सच्च त्यश्च ॥ १ ॥
Brahman has but two forms-gross and subtle, mortal and immortal,
limited and unlimited, defined and undefined.
Adishankara says
Brahman or the Supreme Self has but two forms, through the
superimposition of which by ignorance the formless Supreme Brahman is
defined or made conceivable. The word "Vava' (indeed) is emphatic.
Which are those two forms? The gross and subtle. The other phases of
the gross and subtle are included in them; so they are counted as two
only. What are those phases of the gross and subtle? These are being
mentioned: Mortal, subject to destruction, and inmortal, its opposite.
Limited, which goes a little distance and stops, and unlimited, which
goes on, is pervasive, the opposite of "limited.' Defined, having
particular characteristics that distinguish it from others, and
undefined, the opposite of that, which can only be distantly referred
to, as something we know not what.
Water exists as liquid at room temperature but changes its state to ice at 0 °C. Water exists as liquid, solid and Vapour (Gas). It depends on certain physical conditions. Similarly, Supreme Brahman, who is beyond dualities, is perceived differently by different people. He is the one with form and without form. He is both unmanifested and manifested.
3. BG 7.24 clearly state that God has no avatars? But we still believe in divine incarnations.
This is what Lord says in 7.24 (translated by A Mahadeva Sastry),
avyaktaḿ vyaktim āpannaḿ
manyante mām abuddhayaḥ
paraḿ
bhāvam ajānanto
mamāvyayam anuttamam
Unintelligent men, who do not know Me perfectly, think that I, the
Supreme Personality of Godhead, Krishna, was impersonal before and
have now assumed this personality. Due to their small knowledge, they
do not know My higher nature, which is imperishable and supreme.
Sri Adishankaracharya explains this verses as follows
The foolish regard Me as the unmanifested coming into manifestation, knowing not My higher, immutable, unsurpassed nature.
Not knowing my higher nature as the Supreme Self, theignorant think
that I have just now come into manifestation, having been unmanifested
hitherto, though I am the ever luminous Lord.
Here Krishna never condemns any worship of Saguna form or idol worship. He just says that fools and ignorant people do not know his higher nature which is immutable and unsurpassed. Here Krishna says about His highest nature but this doesn't mean that Lord won't descend by donning Physical body. Lord has both manifested and unmanifested form. He says only few persons know His true form by going into transcendental consciousness. Lord says His true nature at highest level was unborn and imperishable. This is what Adishankaracharya says,
I am not manifest to all, veiled (as I am) by Yoga-Maya. This
deluded world knows not Me, unborn and imperishable.
I am not manifest to all people ; that is to say, I am manifest only
to a few who are my devotees. I am veiled by Yoga Maya. Yoga Maya is
the Maya which is none other than the Yoga or union of the three
gunas. Or, Yoga is the firm will of the Lord or Isvara. The Illusion
or veil thereby spread is called Yoga Maya. Wherefore people are
deluded and know Me not as unborn and imperishable. That Yoga Maya by
which I am veiled and on account of which people do not recognise Me,
is Mine, i. e, subject to My control, and, as such, it cannot obstruct
My knowledge— the knowledge of the Isvara, of the possessor (or
wielder) of the Maya, just as the glamour (maya) caused bya juggler
(mayavin) does not obstruct his own knowledge.
Though Sun is present all the times, we can only see it with normal eyes during day time. Even Lord can only be seen by few of His sincere devotees. Maya stops us from seeing Him and only true knowledge can break that Maya.
This doesn't talk anything about Avatara. Lord says in 4.7
yadā yadā hi dharmasya
glānir bhavati bhārata
abhyutthānam
adharmasya
tadātmānaḿ sṛjāmy aham
Whenever and wherever there is a decline in Dharma (righteousness), O
descendant of Bharata, and a predominant rise of Adharma —at that time
I descend Myself.
So, finally to know proper meaning of Hindu Scriptures either read them in Sanskrit (Veda Bhasha) or in any language with commentaries of knowledgable Acharya or learn them under a knowledgable Guru.
You can read this answer to know how Vedas are preserved. However, some portions of Smriti got interpolated over the vast period of time. But you get essence of Hinduism by reading translations of commentaries of knowledgeable Acharyas.