“The first man is of the earth, earthy: the second man is the Lord from heaven” (1 Corinthians 15:45-47). “Then said He, Lo, I come to do Thy will, O God. He taketh away the first, that He may establish the second” (Hebrews 10:9).
God made a covenant with Israel through Moses, but established another with all mankind through His Son, Jesus Christ. “If that first covenant had been faultless, then should no place have been sought for the second” (Hebrews 8:7). The weakness of that first covenant—the Mosaic Law—was in the fact that the people were too weak by nature for the perfect and holy law: “What the law could not do, in that it was weak through the flesh” (Romans 8:3).
But when Jesus came down from heaven, He—the Second Man—came to establish a second covenant. How foolish of some people today to desire to go back under the first covenant—under abounding sin—when they have the privilege of sharing the benefits of the second and enjoying the superabounding grace which it offers (Romans 5:20). They are constantly working on the first man—the natural man pictured in Adam—trying to make him fit for the presence of God. It is quite amusing, put pitiable, to see these respectable sinners, church-members, trying to make the first man behave like the Second. You might as well order a flashlight to shine like the midday sun. Just think for a moment of the folly of trying to dress up sinful man in religious garments so he will resemble the Lord of Glory. To make the natural man better by education, culture, environment, religion—including the moral teaching of the Second Man—is wholly contradictory to the Word of God which plainly teaches that the sinner’s need is not a better nature, but a new one (John 3:3).
“The law made nothing perfect, but the bringing in of a better hope did” (Hebrews 7:19). The first covenant could not make the first man perfect, nor did it make him imperfect—it simply left him where it found him, in need of the grace of God and a righteous Man to take his place for the violation of the law, because “the wages of sin is death” (Romans 6:23). Christ, the Second Man, came and, because righteous in Himself, was apart from sin and death, but voluntarily offered Himself in the place of every law-breaker who would accept Him and His finished work. He was “delivered for our offenses and was raised again for our justification” (Romans 4:25). Just before He went to the Cross He said, “This is My blood of the new covenant which is shed for many for the remission of sins.” Thereby the Son of God established the second covenant, and now the righteousness unto which the first man can never attain by the first covenant may be obtained by coming to the Second Man and receiving the benefits of the second covenant through the second birth.
How can you be born again? Acknowledge that the best you can do with the first man—your natural self—is to make him a religious and respectable sinner. Confess that—as the first covenant reveals—he is under the condemnation and wrath of God. Immediately flee from Sinai and Moses—where there is only death and judgment—to the Second Man on the cross—where you will find grace and redemption. Calvary is the sinner’s only hope. Salvation does not come by reformation, but by the immediate transformation of a sinner into a saint by the grace of God.
—Condensed from The Second Things of the Bible by J.C. O’Hair