Why did the Lord Himself appear to His disciples during the forty days after His resurrection?
Q364 · Our Lord Jesus Christ, Savior of the World
First : during this time, He taught them about the kingdom of God, whether by His appearances or His teachings (Acts 1:3).
Second : had He ascended to the heavens within a few hours or days of His resurrection, they might have thought that they had just been hallucinating.
Third : during this period, He appeared to others, as the apostle Paul says: “After that, He appeared to more than five hundred of the brothers and sisters at the same time” (1 Cor. 15:6).
693 St. Augustine, Sermons on Selected Lessons of the New Testament, Volume I , trans., R. G. Macmullen (Oxford University Press, 1844) 2.13: pp. 39–40, amended.