It’s a foundational and very important question. Often people who profess to believe the Scriptures say that no one in the Old Testament was regenerated (born again) because that was limited to the New Testament, beginning on the Day of Pentecost.
Such people ought to be asked one simple question–How did David love God’s commandments, even as he says, “exceedingly” loved them? In Psalm 119, David, at least fourteen times, speaks about the heart–his heart being changed, quickened, drawn, and enlarged. Fourteen times he speaks of his relationship with God being one of the heart. Many more times than that he says he loves the truths, ways, purposes, precepts, commandments, statutes, and testimonies of the Lord. Can an unregenerate dead sinner, whose heart is alienated from God, have such a heart and such reality? Impossible.
The one question here is this–Did David have a new heart, a regenerate heart or not? There is no neutral ground here. He was either still spiritually dead in trespasses and sins or he had a new heart that showed itself in loving all that God loved and that cried out to God with purified affection for continual mercy and grace.
The unmistakable truth is that, throughout the Old Testament, Abraham, Noah, David, Joseph, and many others, including the holy women of old (see 1 Peter 3:5) all had a heart that loved and obeyed God. A heart that loves God personally and seeks Him implies and presumes a new heart, a regenerated life.
Therefore, regeneration of the individual believer by the Holy Spirit is both an Old Testament and New Testament doctrine, experienced throughout the Old Testament era, as well as in the New Testament, and must be acknowledged. Otherwise, one is left to believe that those Old Testament believers responded to God with a spiritually dead heart, purely from their own carnal obedience to Mosaic law and no one will dare say that. What professing Christian would say, “Yes, I believe the Old Testament saints were spiritually dead and responded to God with only a legal obedience to the law by their faithful efforts to keep it.” Yet that is what they must admit if Old Testament believers were not regenerated.
Were Old Testament believers regenerated by the Holy Spirit? Of course–there is no other option if the Scriptures are true.
– Mack Tomlinson