As Matthew continues with his narrative, he uses several times the phrase, “From that time on Jesus began…” You may recall that in 4:17 the phrase marked the beginning of Jesus ministry in Galilee, but here in Matthew 16:21, it signals the beginning of Hs journey to Jerusalem and eventual sacrifice on the cross. In fact, we are entering a new phase in which Jesus moves on from educating His disciples concerning His identity to educating them concerning His messianic mission (16:21- 20:34). In this new section, Jesus will be showing His disciples that He must suffer and die in humble submission to God’s will.
Prior to this time, it would appear that Jesus has withdrawn from danger (cf. 12:15; 14:13; 15:21; 16:4). As we continue, we will see Jesus moving inexorably toward the cross. As in the previous section, the disciples will be in every scene, and they will be the primary focus of His teaching, as He teaches them that they must set self aside and live in humble submission to the will of God, even unto death; in all things, they will learn to trust God and God alone.
We will pick up in verses 21-28, as Jesus predicts his death, when we get back together next time; see you then.