The term might be only 400 years old, but the idea of Christ paying the debt we owed through His perfect sacrifice is found from the very beginning.
It is said that 21 For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.
And 1 Peter 2:24 He himself bore our sins in his body on the tree, that we might die to sin and live to righteousness. By his wounds you have been healed.
The fact is that a transaction was made, where Christ took on our sin, and grants us righteousness,
available to those who believe on the Lord Jesus Christ.
Yet neither of those verses say what you implicate them in saying.
God doesn't "grant you righteousness." Those are your words, not the Bibles.
You read the notion of a credited positional righteousness into the text because that is what you have been taught and it is now what you want to believe. It is seeming pretty clear now that you don't seem to much care what the text actually states.
2Cor 5:21 says "MADE the righteousness of God in Him." It says not a word about some positional legal credit. Not only that but the very next verse speaks of WORKING TOGETHER with God lest grace be received to no effect.
2Co 6:1 We then, as workers together with him, beseech you also that ye receive not the grace of God in vain.
Grace can be received in vain if one does not cooperate with God. That means there is something we have to do.
Penal Substitution teaches that there is NOTHING we have to do because it has already all been done. All one has to do under the Penal Model is "trust" that it was done. It is a lie, yet you believe it.
1Pet 2:24 is speaking of an example set forth.
1Pe 2:21 For even hereunto were ye called: because
Christ also suffered for us, leaving us an example, that ye should follow his steps:
1Pe 2:22 Who did no sin, neither was guile found in his mouth:
1Pe 2:23 Who, when he was reviled, reviled not again; when he suffered, he threatened not; but committed himself to him that judgeth righteously:
1Pe 2:24 Who his own self bare our sins in his own body on the tree,
that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed.
We die to sin WITH Jesus and thus live unto righteousness.
Rom 6:4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
Rom 6:5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
Rom 6:6 Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
Rom 6:7 For he that is dead is freed from sin.
Rom 6:17 But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.
Rom 6:18 Being then made free from sin, ye became the servants of righteousness.