Gerhard and Walther

It is not only idolatry if a person wants to regard and glorify as God that which of itself by nature is not God, even though it is merely a created creature or an image formed by the hand of man. Instead, it is also idolatry if a person wants to serve the true God in a different manner than what God has commanded and prescribed. For thereby a person serves not the true God but rather he serves the idol that a person has established in his own heart.—Johann Gerhard, Schola Pietatis III:32,33.

Of course God does not always answer prayers immediately. He sometimes lets the petitioner wait for a longer or a shorter time… God often allows delays for the wisest reasons. He alone knows the hour in which the requested help or the good will be salutary. He also uses the delay to awaken us, perhaps for the first time, to true earnestness in our asking.—C. F. W. Walther, God Grant It!, p. 423.