Salvation : to be saved from death unto eternal life.I use regeneration, salvation and justification interchangeably, I see no reason to view the three as professing different doctrines unless you are willing to describe how this is.
Justification : To be rendered righteous.
Regeneration : To be made anew - a new heart, a new spirit, a new birth.
Case 1: God saves people through justification by faith in Christ - but as they are in the flesh, without making them a new creature in the spirit. This throws an impossibility because the flesh cannot inherit the kingdom, being condemned for sin in it (Rom 8:3).
Case 2: God saves people after regenerating them - but not through justification by faith in Christ's sacrifice for the sins of the world. This is yet another impossibility for it makes God to be unjust when He justifies people by simply overlooking/ignoring their sins(Rom 3:26).
Case 3: God regenerates people and justifies them in Christ - but does not save them. An impossibility, since God would be unjust to condemn those who're rendered righteous.
Case 4: God first saves people into the Kingdom of God - and then regenerates and justifies them. Impossible - regeneration must precede salvation since the flesh cannot inherit the Kingdom of God, and justification must precede salvation for until the atonement is applied, people will die in their sins.
From the first 3 cases, I seek to establish the distinction between the three concepts - and why they have to go together. In Case 4, I seek to show that these concepts do follow an order of sequence, with Salvation necessarily being the final step.
We also know, similarly, that justification and faith are distinct concepts - for in one case, one may be justified by the law while in another case, he may be justified by faith. And we know that that with which you are justified must necessarily precede the justification itself - hence faith must precede justification.
And we know that John's baptism/ministry of repentance preceded faith in Christ(Acts 19:1-5). And that's where I posit that for a person to repent, he must have his stony heart removed lest he simply harden it more against God - thereby requiring the newness be made in him for him to be enabled to repent and believe. That's how I arrive at regeneration preceding repentance and faith.
Now - regeneration, repentance, faith are what man ought to do(Eze 18:31, Mark 1:15) - while God responds with justification, adoption, sanctification and preserving in the promised Holy Spirit...right unto salvation.
God commands, exhorts and pleads with man to fulfill his part and promises the rest upon that. Not one obeys - no, not even the elect - for all are hardened in their hearts and rebel against God in sinful flesh.
God, at this point, is perfectly Righteous to condemn one and all as per His Just wrath - for even the elect fall under this predicament (Eph 2:3). But therein,
Rom 9:29 And as Esaias said before, Except the Lord of Sabaoth had left us a seed, we had been as Sodoma, and been made like unto Gomorrha.
Rom 9:27 Esaias also crieth concerning Israel, Though the number of the children of Israel be as the sand of the sea, a remnant shall be saved:
Rom 11:5 Even so then at this present time also there is a remnant according to the election of grace.
God, before the foundation of the world, and before any had done any good or evil(Rom 9:11), reserved for Himself the elect whom He vowed to have His everlasting mercy upon, lest they fall as Sodom - therein predetermining to successfully fulfill His purpose to have a people for Himself. And to this end, He kickstarts the salvation process by regenerating the elect, out of His mercy. He does this not for their sake, for they are a stiffnecked and rebellious people too(Deut 9:4,6), but for His own Holy Name's sake(Eze 36:22). And it is this regenerated newness that makes the Gospel call seem new - while it is the selfsame Gospel call preached earlier to their hardened hearts. The difference is in them, not in the calling. This triggers the domino effect of the now renewed creature to willingly repent and believe in Christ to which God responds as promised.
Note, God's promises are to all, not based on whether they're elect or non-elect - if any will put in themselves a new heart and a new spirit(by seeking and asking God) and consequently repent and believe, God will deal with them the exact same way. But alas, none seek God - all are gone out of the way and are unprofitable - each walking according to their own sinful flesh. How then is God not justified in extending His mercy to the elect - for He will have mercy upon whom He will have mercy(Rom 9:15).
Therefore, it is true that God offers salvation to all, and yet only the elect are saved. It is true that man cannot but sin in the flesh, and yet man is held responsible for his sins. It is true that everyone is held responsible for their sins, and yet only the elect have their sins atoned. It is true that man is commanded to repent and believe and that eventually it is he who does so, and yet salvation is monergistic.
Whew. Need to catch my breath.