The answer you want to hear is to glorify God. My answer includes that, but doesn't stop there. Not only to glorify God, but to provide Him with beings who love him of their own decision, to provide companionship. Beings created and then forced to glorify him are no more than computer programs--not companions.
And before anyone takes my words out of context--no, I do not mean we shall be as God, or as gods, or however else you may put it.