Does prayer make sense?

If you believe in God and think that he/she is all powerful, then isn’t prayer rather presumptuous? The person praying is lobbying god for a specific outcome, which god (remember the assumption is that it is all powerful and knows what it’s doing) may or may not have had in mind.

On the flip side, if prayer is effective (i.e. god changes its mind) then does that not imply that God is not perfect and infallible if its actions can be changed.

So, is god infallible and prayer useless?

or is god not godly if prayer has an effect?

Either way, it seems that religious-based prayer is on shaky ground.