John Piper on preaching:
The cross is also the ground of the humility of preaching because the cross is the power of God to crucify the pride of both preacher and congregation. In the New Testament the cross is not only a past place of objective substitution; it is also a present place of subjective execution– the execution of my self-reliance and my love affair with the praise of man. “Far be it from me to boast except in the cross of our Lord Jesus Christ, by which the world has been crucified to me, and I to the world” (Gal. 6:14).