What does Mark 8:30 mean?

When we are asked why God sent Jesus when He did, at least one valid reason is because they didn't have social media back then. Excessive publicity and a lack of context would have made Jesus' ministry that much harder. Jesus keeps—or tries to keep—short reins on the publicity of His ministry. He turns the water into wine out of respect for His mother, not because He is ready to be known as a miracle-worker (John 2:1–11). He silences demons because He does not want them to be the witness of who He is (Mark 3:11–12). When His brothers cynically push Him to reveal who He is, He tells them His time hasn't come (John 7:3–8).

But when Jesus is walking through the garden of Gethsemane, He warns Peter, James, and John that it is time for His sacrifice (Mark 14:41). Even to the last minute, moments before He ascends into heaven, the disciples ask if it is time to restore the kingdom to Israel; He tells them not yet, there is work to be done (Acts 1:6–8). In fact, even He does not know when He will return (Mark 13:32).

The issue of timing plays a role in why Jesus does not yet want the disciples to spread the news that He is the Christ. They need to know because it brings context to what He will teach them privately. But if the people find out, they will get ahead of themselves, and try to make Him king (John 6:15; Mark 11:9–10). Before the disciples proclaim that Jesus is the Christ, they must first understand that the Christ has not come to save Israel from the Roman Empire but to save the world from sin (John 3:16–17). Peter proves they are not ready when he rebukes Jesus after Jesus says He must be killed (Mark 8:31–32).

"Charge" is from the Greek root word epitimao. In other places, the word is translated "rebuke." When Jesus uses this word, it is with the authority of God (Mark 1:25; 3:12; 4:39; 8:32). When other people "rebuke" in Mark's Gospel, they are being presumptuous (Mark 8:33; 10:13; 10:48), getting in the way of Jesus doing His job. Rebuke has its place (1 Timothy 5:20; 2 Timothy 3:16; Titus 1:13), but the instances performed by people other than Jesus in this Gospel are inappropriate.