There are many passages in Hindu scripture that praise murti puja.
Henceforth, I shall mention the benefit accruing from the installation
of the idol entirely, for the welfare of the world. The idol may be in
accordance with one’s own wish.
Linga Purana I.76.1
Image worship and love of humans
I abide in all beings as their inner-most soul. Disregarding My
presence within them, men make a show of worshiping Me through images.
If one disregards Me present in all as their soul and Lord but
ignorantly offers worship only to images, such worship is as
ineffective as a sacrificial offering made in ashes. A man who
persecutes Me residing in others, who is proud and haughty, who looks
upon God as the other – such a person will never attain to peace of
mind. If a man disregards and persecutes fellow beings, but worships
Me in images with numerous rituals and rich offerings, I am not at all
pleased with him for proffering such worship. A man should, however,
worship Me in images, side by side with discharging his duties, which
include the love of all beings, until he actually realises My presence
in in himself and in all beings. As long as man is self-centred and
makes an absolute distinction between himself and others (without
recognising the unity of all in Me, the Inner Pervader), he will be
subject to the great fear of Death (including every form of
deprivation of self-interest). So, overcoming the separateness of a
self-centred life, one should serve all beings with gifts, honour and
love, recognising that such service is really being rendered to Me who
reside in all beings as their innermost soul.
Srimad Bhagavata Purana III.29.21-27
Till the realisation of perfect knowledge a man should continue the
ritualistic worship of Shiva. In order to convince the world,
the rituals must be continued.
Just as the sun is reflected in many vessels, in the same manner, O
devas, know that the supreme Brahman, Shiva, assumes the form of
whatever is seen or heard in the world real or unreal. There is
difference in vessels but not in the water they contain.
This is what those who know the real meaning of the Vedas say. "Lord
Shiva is within the heart of beings in this world." Of what avail are
images to those who have the real knowledge?
Having an image is very auspicious for a person who has no such
knowledge. It is a ladder that enables him to climb to a higher
position.
It is very difficult to climb to a position without a support. The
image is only a means to achieve the Nirguna Shiva.
The attainment of the Nirguna through a Saguna is certainly possible.
In this manner, the symbols of all lords are conductive to steady
faith and belief.
This lord is very great and this is the mode of worship of that lord.
If there is no image, of what avail are scents, sandal paste, flowers
etc?
Till the realisation of true knowledge, the image shall necessarily be
worshipped. If any one does not worship the image before he attains
perfect knowledge, his downfall is sure.
Shiva Purana, Rudra Samhita, Section I, Creation, Chapter 12
In every figure he hath been the mode; this is his only form for us to
look on. Indra moves multiform by his illusions; for his Bay Steeds
are yoked, ten times a hundred.
Rig Veda VI.47.18
Basic elements of Murti or Pratima Puja is there in the Rig Veda itself. The idea that a Devata can enter every figure and has many forms allows one to do Murti puja.
