As Christians we must constantly remind ourselves both of the complexities and the glorious depths of the mysterious gospel of Christ, and of its ability to be summarized in a gloriously simple statement. We must keep checking ourselves! Do we actually believe what the Bible says? This is, to me, a fantastic summary of the message all Christians are meant to proclaim:
[Jesus] deliberately went to the cross and suffered the shame and the spitting and the indignity of it all; and this He did to bear my sins; to receive my punishment; to suffer the penalty that my guilt had deserved; and infinitely more important, to deliver me from the bondage of sin and of Satan; to separate me unto Himself; and to make of me a man zealous of good works, delighting in holiness. He died; He was raised from the dead; He returned to heaven, and He sent down the Holy Spirit on the day of Pentecost in order that I might have the assurance of my faith, and the joy, and the power. He has given me a new life and a new nature; He has joined me unto Himself; I am a member of His mystical body; I am a child of God, I am an heir of heaven.
That is what knowing Christ means, learning Him, hearing Him, being taught in Him! I believe the teaching that nought that defileth shall be allowed to enter into heaven; that heaven is eternally pure and holy, the antithesis of this world and sin, the opposite to hell. That is how I have learned Christ, that is how I have heard Him, that is how I have been taught in Him—that I am in Him the living Head, and a part of Him; and that beyond this life and death and the veil, I am going to be with Him forever and forever. If you believe these things, says Paul, you will ‘have no fellowship with the unfruitful works of darkness’.
David Martyn Lloyd-Jones, Christian Unity, Studies in Ephesians, chapter 4, verses 1 through 16 (Grand Rapids MI: Baker Book House, 1972), 115. Also available electronically from Logos Bible Software.