Why do we need God ? On a basic physical level of survival, God gives us sunlight, water, air and food grains without which we cannot survive. God is bhukta, the maintainer, man is bhakta, the maintained. Man is ever in the dependent position.

Why do we search for God ? "Athato brahma jijnasa" We search for God because only in this rare and valuable human form of life do we have the requisite intelligence to question our own existence and ask relevant questions like "Who am I ?," "Who is God ?," and "What is my relationship with God ?" Just think about the fact that there are 6 billion humans on earth. That seems like a lot until we consider how many countless billions of insects, birds, fish and animals must inhabit the earth. Therefore, the human birth is truly rare and we should make the best use of our God-given intelligence and solve the issue of mortality.

Hope this helps.
jeffster/AMdas