The problem with prayer is getting the answers you want.
After all, when we pray, we are asking God for something. It’s called Petitionary Prayer. Even C.S. Lewis wrote a treatise on the subject. Other types of prayer are much easier to deal with. If your prayer is worship, then you aren’t expecting necessarily an answer. If your prayer is intercessory, you may be looking for God’s intervention but we all know that he works “in mysterious ways.”
Petitionary prayer is where the problem is found. It is specific and usually detailed and there is not much room for misunderstanding. The problem is that God often simply doesn’t give us what we want. Perhaps we fall into the trap of trying to appease God in order to get what we want by going to church, making promises, tithing or the like. That isn’t going to work. God hates it when people try to manipulate him (my wife feels the same way).