थे तेअचिंग ऑफ़ थे APOSTLES

The Teaching of the Apostles
Jesus' apostles were the main witnesses of his life, teaching and resurrection from the dead. They are believed by most Christians to have written some of the New Testament's Gospels and Epistles.

Does the Christianity presented to us in the rest of the writings of the New Testament differ from that described in the Gospels? And if so, is the difference one of kind or one of degree? Christianity was never meant to be fully set forth in the Gospels, where it is presented mainly in action.

"I have yet many things to say to you: but you cannot bear them now", said Christ in His last discourse. "But when he, the Spirit of truth is come, he will teach you all truth . . . and the things that are to come he shall show you" (John, xvi, 12, 13).

We may presume that Christ Himself told them these many things when "He showed himself alive after his passion, by many proofs, for forty days appearing to them, and speaking of the kingdom of God" (Acts, i, 3), and that they were rendered permanent in the minds of the Apostles by the indwelling of the Spirit of Truth after Pentecost.

Accordingly, we must expect to find in their teaching a more formal, more theoretic, and more dogmatic exposition of Christianity than in the drama of Christ's life. But what we have no right to expect, and what rationalists always do expect, is to find the whole of Christianity in its written records. Christ nowhere prescribed writing as a means of promulgating His gospel. It was comparatively late in the Apostolic Age, and apparently in obedience to no preconceived plan, that the sacred books began to appear.

The main heads of the Apostolic preaching, as far as we can gather from the records, vary with the character of the audiences they addressed. To the Jews they dwelt upon the marvelous fulfillment of the prophesies in Christ, showing that, in spite of the manner of His life and death, He was actually the Messias, and that their redemption from sin had really been accomplished by His sacrifice on the Cross. This was the burden of St. Peter's discourses (Acts, ii and iii) and those of St. Stephen and all who addressed the Jews in their synagogues (cf. Acts, xxvi, 22-23).

http://www.newadvent.org/cathen/03712a.htm

http://www.spaceandmotion.com/christianity-christian-jesus-christ.htm