The paradox of prayer: Henri Nouwen

"The paradox of prayer is that it asks for a serious effort
while it can only be received as a gift.
We cannot plan, organize or manipulate God;
but without a careful discipline, we cannot receive Him either." By the way, I have recently been slow reading his classic "The Return of the Prodigal Son" and feasting on the insights on every page. Grab it if you ever see it on sale.