Hindu's pray so that they may be with God all the time. Hindu's seek union with God, in this world, and in the next.
Hinudu's believe the goal of life is union with God. This can be achieved in this life before it ends. This is called jivan-mukti, self realisation.
Prayer in Hinduism unites all aspects of life, all activity, with the activity of the Divine. Action is done for the sake of the action only. Devout Hindus perform nishkama karma, selfless action which is offered to the divine; they are free from the results of the action, and thus, acquire no new karma.
Divinity in Hinduism extends to all parts of life; there is the family God, the personal God, the Temples, the Festivals. God permeates and interpenetrates all activity, One of the sayings in Hinduism is easwara sarva bhuthanam thwam, God is the doer of all actions. Hindus understand that their soul is a spark of the divine itself, on a journey back to the divine, to be united with itself.