What is the importance of God in our lives?

If God created us, it is important to know why He created us, so we can fulfill that purpose. That is the only criterion of a successful life.

In the Holy Quran it says:

creation

And I have not created the Jinn and the men but that they may worship Me. (51:57)

Worship means to subject oneself to a rigorous spiritual discipline, working with all of one’s inherent powers and capacities to their fullest scope, in perfect harmony with and in obedience to God’s design, so as to receive the Divine impress and thus be able to manifest in oneself God’s attributes.

This is the great and noble aim and object of man’s creation and this is exactly what worship of God means.