"And withut controversy great is the mystery of godliness:God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the gentiles, believed on in the world, received up into glory."
This 'mystery' is not of that same kind as the Gnostics, which was only revealed after certain elaborate initiation rites and oaths had been performed and taken. Rather, this 'mystery of godliness' is indeed the Gospel of our Lord and Saviour Jesus Christ, which is to be clearly and thoroughly preached and taught to all mankind, 'in season and out of season', without compromise or reservation.The main points to note are....
[1] Christ took upon Himself humanity; He came and was born as a man;He ' took on flesh'. Hebrews 2:14 gives us the reason for this..."Forasmuch then as the children are partakers of flesh and blood, He also Himself likewise took part of the same: that through death He might destroy him that had the power of death, that is, the devil."
[2]By the Presence of The Holy Spirit throughout Christ's Ministry, He was vindicated and proved true in all His claims.John the Baptist recorded the following in The Gospel of John 1:33,34..."Upon Whom thou shalt see the Spirit Descending and Remaining on Him...This is The Son of God."
[3] Christ appeared to angels in...{a} His Resurrection..(John 20:11-12.). {b} His Ascension....(Acts1:10-11). {c}His Entrance into Heaven...(Heb.12:22-24).
[4] 'Christ Being 'preached among the nations' is a summary of the entire era of missionary work.(Matt.24:14)
[5] The whole Messianic work of Christ is summed up in this verse, which is widely held to be a hymn of praise, poetic in nature. (1 Cor.15:1-8).
May The Lord Bless you.