The term 'substitutionary atonement' has been used within Trinitarian, Protestant, Reformed Baptist circles for some time, and it is those I wish to examine in this question.
But the word 'substitute' does not translate a Greek word found in scripture, nor does the term 'atonement'. The word 'atonement' is found once in the KJV, Romans 5:11, but it is a clear mis-translation of the word καταλλαγην, katallagen, in all other places rendered 'reconciliation'.
Both words are vague in meaning. Nor does 'substitute' or 'substitution' convey a concept that the apostolic epistles express, the emphasis of the doctrine of Christ being union with Christ (in his sufferings, in his death and in his resurrection) rather than some kind of 'exchange' (another word never found in Greek except μετηλλαξαν, metellazan, in Romans 1:26).
The word 'atonement' has a weak etymology and an ill-defined concept, its meaning a loose 'at-one' derivation and its application being a very general and overall term for the both the sufferings and death and resurrection of Christ that is never found in the greater precision of the apostolic writings.
What exactly is being conveyed by the term ? When was the expression first coined ? What error was being resisted by the introduction of this couplet ?
Again, I am looking for a response in regard to Trinitarian, Protestant, Reformed and Baptist usage of the terminology.
EDIT upon comment :
I believe that 'Christ died for our sins, according to the scriptures'. I believe that 'Christ gave his life a ransom for many'. I believe that 'He bare our sins in his own body on the tree'. I believe that 'he was made sin for us, who knew no sin'. But the scripture never uses the word 'substitute' to express that. I am questioning the terminology, not the doctrine of Christ.
Further explanatory EDIT :
My concern has always been the emphasis. If I have no relationship with Christ, if I am not in union with Him, if I know not his presence before my face when I pray, then the facts of his sufferings, death and resurrection are just that - historical facts.
The terms 'substitute' and 'exchange' are distant terms. But kinsman-redeemer, for example, (gaal in Hebrew) conveys a relationship that exists before the redemption takes place, (see the book of Ruth, on this). And one is chosen 'in Christ' (not apart from him) before the foundation of the world.
These are my concerns and the reason for my question.