It’s one thing to speak the truth to people in power when you have nothing to lose. It’s quite another to speak the truth when you have everything to lose. The Old Testament prophet Nathan faced the prospect of losing everything, including his life, if he spoke the truth to the most powerful man in Israel. Yet that was exactly what God called him to do.
This verse is part of Jesus’ prayer of agony in the Garden of Gethsemane before His arrest and crucifixion. This “cup” to which He referred was the suffering He would endure on the cross as an atoning sacrifice for sin.