[annalex]

Catholicism believes mary was immaculately conceived...yet their own apologists admit this cannot be substantiated in Scripture

You switched the subject. The Immaculate conception is not spelled out in the scripture, but it does not contradict the scripture. The key Protestant doctrine of salvation by faith alone, however is not simply extraneous to the scripture, the scripture teaches that it is false (James 2:17-26). Sola Scriptura is not anywhere in the Bible, but the idea of Sola Scriptura is that everything important to faith is in the Bible. If that were true, Sola Scriptura would be taught by the Scripture. It is not. That is a another Protestant contradiction with the scripture, and these two are the foundational falsehoods of Protestantism.

[CynicalBear]

>>The key Protestant doctrine of salvation by faith alone, however is not simply extraneous to the scripture<<

Romans 4:5 But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness. 6 Even as David also describeth the blessedness of the man, unto whom God imputeth righteousness without works,

[redleghunter]

James also said in the same discussion:

James 2:
23 And the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness: and he was called the Friend of God.

So there is that right in the middle of James point.

The misunderstanding comes when people pluck verses from context.

[xone]

but it does not contradict the scripture.

Requiring it to be believed for salvation contradicts the scripture.