The message of Christianity is one of self-distrust. You cannot do it on your own. We hate hearing this because we feel like it denies or limits our power. "I have the power" we say to ourselves, "I'm confident I can do this, build this, become this." Jesus doesn't think so.
Confidence is a compound word meaning With Faith, to have faith in one's own ability to accomplish, to succeed. The gospel tells us to stop having confidence in ourselves. We cannot accomplish. We cannot succeed. Apart from Christ, "you can do nothing."
I said this is a part of the gospel message, which means that it is supposed to be "Good News". How is this good news? Are not the greatest and most powerful among us men and women who had confidence in themselves, who excelled in their abilities?