It would be easy to answer...for nothing, it is a waste of time !
Prayer is a free act, and this is already one of its values.
Why ask for more in our prayers, than what it already does ?Put us into a relationship with God ?
Actually, prayer can offer a lot. It gives us peace in our hearts, strength to live, comfort.
Prayer helps us to be clear-sighted, and to remain focused on the essential. It is in prayer that we can find our hope.