Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come.
God promised: “Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh.” (Ezekiel 36:26)
Calvinist, D. James Kennedy, writes: “Even as the serpent sloughs off its old skin and becomes completely new, so also the whole man, born spiritually dead, casts off his old life and becomes a new creature.” (Why I Believe, p.132)
Calvinist, James White, writes: “When the time comes in God’s sovereign providence to bring to spiritual life each of those for whom Christ died, the Spirit of God will not only effectively accomplish that work of regeneration but that new creature in Christ will, unfailingly, believe in Jesus Christ (‘all that the Father gives Me will come to Me’). Hence, we are not saved ‘without’ faith, but at the same time, Christ’s atonement is not rendered useless and vain without the addition of libertarian free will.” (Debating Calvinism, p.191, emphasis mine)
This quote demonstrates that Calvinists do teach that one must become the new creature in Christ before he can repent, believe and become saved. But Ephesians 1:13 states: “In Him, you also, after listening to the message of truth, the gospel of your salvation--having also believed, you were sealed in Him with the Holy Spirit of promise.” This shows that you are not sealed as a Born Again, new creature in Christ until after you have first heard and believed in the Gospel.
John Calvin writes: “I admit that contumacy is common to all, nor is the heart any flexible and obedient to God until He gives what He commands. For why are we called new creatures, unless because we are remade of God, created to every good work (Eph 2:10; II Cor 5:17)?” (Concerning the Eternal Predestination of God, p.107, emphasis mine)
According to Calvin, since man is totally depraved and totally unable to come to Christ, God must remake him into a new creature in order to come to Christ. In other words, man must be regenerated, preemptively, in order to come to Christ, irresistibly. However, the new heart and the new spirit as a “new creature” are solely reserved for those who are in Christ. So now the question arises, can a person be in Christ before he hears and believes in the Gospel? No. Whereas there is no condemnation in Christ, as per Romans 8:1, there is indeed condemnation for the unbeliever, as per John 3:18. In other words, you cannot have people in “in Christ” while simultaneously being in a state of unbelief.