David became the butt of jokes, of sarcasm, even of bitterness because he was zealous for God. David put his whole heart into obedience to God, into talking about God, into trying to get people to turn to God, setting a right example for God. So, instead of winning people over, they told sarcastic and dirty stories about him. Because of his zeal for God, He became a reproach.
Believe it or not, this will happen right in the church, in the fellowship of God's people. It is almost guaranteed that if a person displays more than usual enthusiasm for God, studies a lot, and talks a lot about God and His Word, even members will avoid him, and some will probably be offended.
Have you ever had somebody say to you, "Come on! Loosen up a little bit." My wife and I have had that said to us by church members: "Come on, sin a little bit, Ritenbaugh." They were offended.
Such things will happen right in the church—it happened to David. Israel, at the time, was God's "church" in terms of being God's people. Right in His congregation people were reproaching David because of his zeal for God.
John W. Ritenbaugh
Prayer and Seeking God