Greatest Theme of the Bible from Genesis to Revelation:  The Oneness of God

And without 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.  1 Timothy 3:16

Water and Spirit Baptism

Bible answers as to why the apostles baptized in Jesus’ name.

Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.  Acts 2:38

Repentance:  The Pathway to Salvation

And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.  Luke 24:47

Introduction:  Warning Not to Lose the Doctrine

Beloved, when I gave all diligence to write unto you of the common salvation, it was needful for me to write unto you, and exhort you that ye should earnestly contend for the faith which was once delivered unto the saints.  Jude 1:3