Okay, let’s exegete this (since you refuse to engage in exegesis):
10For if,: That is to say, ‘if it is true that’
when we were enemies,: at the point in which all men are naturally, “for all have sinned and fall short of the glory of God” as previously established in Rom 3:23; if this is true, then it is also true that at that point
we : All who have sinned and fallen short
were reconciled to God by the death of his Son,: If it is true that all have sinned, then reconciliation is equally for all that have sinned. This expressed again in
Rom 5:18, “Consequently, just as one trespass resulted in condemnation for all people, so also one righteous act resulted in justification and life for all people.”
The “all people” in 5:18a and the “all people” in 5:18b have to be the same in identity, which is consistent with my interpretation of this verse.
much more, being reconciled, we shall be saved by his life: here the “we” is necessarily restricted to believers, who have already believed, and therefore have the future expectation of “being saved” by his triumph over death in the resurrection.
5:19 mimics this again saying
“For just as through the disobedience of the one man the many were made sinners, so also through the obedience of the one man the many will be made righteous…” who believe in Christ. Salvation is available to all who believe! For the overarching purpose of God was that, as Paul says in 5:20-21,
“The law was brought in so that the trespass might increase. But where sin increased, grace increased all the more, so that, just as sin reigned in death, so also grace might reign through righteousness to bring eternal life through Jesus Christ our Lord.”
“Might reign” (βασιλεύσῃ) is in the subjunctive which is the mood of probability and potential. It will happen if and when believing occurs. All have the potential for believing and thus grace might reign for “all who have sinned and fallen short of the glory of God.” As Paul later says in Rom 10:9, “If you declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved.
If the conditions of “declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead”, then “you will be saved”!
The language cannot be understood in any other way. Belief (and confession of Christ’s Lordship) results in salvation. Not the other way around.
Doug