As far as I understood, Advaita Vedanta does not require the concept of Trimurti and other gods. Therefore one can reach enlightenment without believing or worshiping any God. But we live in a society where idol worship is very popular. How can I merge the concepts of one god with many gods? What is the point of making it more complex?
The word God has many meanings and connotations to different people - in different religions also. It's best in a question like yours to be more exact. The Advaita Vedanta asserts that there is only the self-existent, eternal, unchangeable referred to as Brahman. What it is cannot be said, all that can be said is that it is not two.
Pure Advaita says that the universe is not really as it appears, that it is all Brahman, that there was no creation, there is only an 'apparent' creation. You cannot become enlightened - you are already the Eternal One. To think that you can become enlightened means that you are already under the spell of delusion. You were never unenlightened, you have always been Brahman.
The Astavakra Samhita (VII. 2-3) says (translator Swami Nityaswarupananda):
In me, the limitless ocean, let the wave of the world rise or vanish of itself. I neither increase or decrease thereby.
In me, the boundless ocean, is the imagination of the universe. I am quite tranquil and formless. In this [Realization] alone do I abide.
and further in XX. 2-7:
Where are the scriptures, where is knowledge of the Self, where is the mind not attached to sense-objects, where is contentment, and where is desirelessness for me who am ever devoid of the sense of duality?
Where is Knowledge [of Brahman] and where is ignorance; where is 'I', and where is 'this', and where is 'mine'; where is bondage and where is liberation? Where is an attribute to the nature of my self?
Where are prarabdha karmas, where is liberation-in-life, and where is even liberation-in-death for me, the ever undifferentiated?
Where is the doer or enjoyer, where is cessation of thought or the rising of thought, where is direct knowledge or reflected knowledge, for me who am ever impersonal?
Where is the world and where is the aspirant for liberation; where is the contemplative man and where is the man of Knowledge; where is the soul in bondage and where is the liberated soul for me who am non-dual by nature?
Where are creation and destruction; where is the end and where the means; where are seeker and success for me abiding in my non-dual state?
and in XX. 11:
Where is illusion, where is the world; where is attachment or detachment; where is jiva or Brahman for me, who am ever pure?
Swami Vivekananda says (Complete Works, V4, p 246 and here - (http://cwsv.belurmath.org/volume_4/vol_4_frame.htm):
Realize yourself. That is all there is to do. Know yourself as you really are--infinite spirit. That is practical religion. Everything else is impractical, for everything else will vanish. That alone will never vanish. It is eternal. Hospitals will tumble down. Railroad givers will all die. This earth will be blown to pieces, suns wiped out. The soul endureth forever.
and in V1, p 257 (http://cwsv.belurmath.org/volume_1/vol_1_frame.htm) he says:
The aim is to get rid of nature's control over us. That is the goal of all religion. Each soul is potentially divine. The goal is to manifest this divinity within, by controlling nature, external and internal. Do this either by work, or worship, or psychic control or philosophy--by one or more or all of these--and be free. This is the whole of religion. Doctrines, or dogmas, or rituals, or books, or temples, or forms, are but secondary details.
and again in the Astavakra Samhita (I. 11):
He who considers himself free is free indeed, and he who considers himself bound remains bound. 'As one thinks so one becomes' is a popular saying in this world, and it is quite true.
Realize who you are already and be free.