This is an excerpt from Deivathin Kural(Voice of God). Let us dive in to the subject.
Whenever we see a house, we know that there must be a builder, an engineer for it. For everything in this world, we know that there must be a creator for it and he/she can be identified. Therefore, we all agree that there is nothing in this world that got created by itself. We also agree that everything in this world is created by putting together one or more things that obey certain laws(Science).
But we aren't able to point out someone who created a banana tree. We aren't able to find the creator of the moon, sun and the celestial bodies. But there should have been someone behind the creation who decided the shape and use of it.
Shouldn't there be a creator for the entire world that functions obeying certain laws? Shouldn't there be one who puts together many elements to create various elements of nature for specific purposes? Thus, it is evident that there must be a great power behind creation and regulation of the world. Everything in this world obey the same rules and regulations. Therefore, everything in this world must be created by one power. The one power is what we refer to as 'God'. The Vedas repeatedly mention that the power(God) is hidden inside a cave. The cave is just our heart. He is the one who does everything and he is the one who makes us search for him. The hunt for God is referred as 'Bhakti'.
If we see a yellow banana and someone calls it red, we aren't able to accept it. At the same time, when someone asks us to imagine the banana as red, we seem to show some kind of acceptance. We are able to actually imagine it as red when we show more concentration. Worship of Gods is also similar to this. The Upasana Marga describes God with several forms and qualities. But God is actually beyond all forms and qualities. The reason we worship Gods with forms and qualities is that we tend to show some kind of acceptance than worshipping a formless God. By describing Goddess Durga sitting on a lion with several weapons, we are actually able to picturize the creator of the world. The Supreme Soul has actually become such forms, and has also become the Mantras, Yantras, and Tantras that reach them. Therefore, worshipping with strong belief is actually the path towards knowledge.This kind of worship can stand still until we realize the True God, that is we attain Gnanam(Knowledge). Until we realize the True God, we are bound to several rules and regulations for worship. Once we realize God, there are no rules for worship. Devotion is all about belief and affection towards the Supreme.