The context for Jesus’ remarks is the hostility that resulted from His denunciation of the Jewish leaders (11:37-54). A huge crowd gathered, with so many people that they were stepping on each other. Jesus spoke primarily to His disciples, but in the hearing of all, warned them about the leaven of the Pharisees, which is hypocrisy. He was drawing a line: people could follow the leadership of the Pharisees or they could follow Him. But they must make a choice and stick with it in the face of potential persecution and even death. To try to straddle the line will bring a person into ultimate and final judgment. Thus,
We must beware of hypocrisy and confess Christ, even unto death, because hypocrites will face God’s judgment.