It was probably out of consideration for his followers, as there might be a popular rising which might lead to slaughter. The people were expecting the Messiah to be a king and, if they had recognized Christ, and still held that notion they would probably have risen in rebellion against Rome. On one occasion (John 6:15), he hid himself to prevent such a rising. It was safe after his death to preach him as the Christ, because then the spiritual nature of his kingdom would be understood; but while he lived, it was necessary to avoid publicity. Even the disciples expected that he would make himself king and did not understand his real purpose until after the resurrection.