Actually if you read a lot of powerful preachers of the past, many of them spent hours upon hours in their prayer closet. Prayer is the one thing the majority of the Church is missing, which is why it is so dreadfully weak. I always wondered how come the Old Testament saints had such close communion with God, yet us, with the better promises and better covenant, have a far more limited communion, something isn't right here, either the new covenant isn't better or we're flat out not even bothering to use it.