Personal one on one with Baptists---not good for me. You are a better man than I am in this area.
However, using Sola Scriptura against them has distinct advantages. Take for example the Doctrine of Baptism. They say they get their doctrine from Scripture, but in examining their arguments it is anything but.
First of all, they say baptism is SYMBOLIC. Where to they get that notion? The greek word "Symbolia" is not found in the NT nor in in the LXX. Nor does any passage of Scripture hint at such a thing. This interpretation is an innovation and therefore not apart of Sola Scriptura.
The usage of the Didache for their belief in immersion baptism. This is not Scripture, it is extra Biblical....therefore rejected by sola Scriptura.
The constant appeal to "most Scholars believe immersion baptism is the only baptism"..."Objection your honor! Sola Scriptura....this is an appeal to authority outside of Scripture. Strike the comment from the record." Gotta love the court room language there.
Their definition of baptism such as "outward sign of an inward change" is not found in Scripture. This definition is an innovation. This violates sola Scriptura.
There are a lot more "innovations" we can comment on.
The usage of the word "innovation" has devastating effects on the credos. It should be used more by paedos.
The most amazing thing about this whole process of pointing out innovations in others, we are thinking about the innovative beliefs of ourselves. AND THIS IS A GOOD THING.
I like that you are using a "sola scriptura" test. But in this case - the Baptists are right.
1 Peter 3 is clear that the touch of sacramental waters does nothing at all. rather the saving aspect is the "appeal to God for a clean conscience" by the one being baptized.
1 Peter 3:20 who once were disobedient when the patience of God kept waiting in the days of Noah, during the construction of the ark, in which a few, that is, eight persons, were brought safely through
the water. 21 Corresponding to that, baptism now saves you—
not the removal of dirt from the flesh, but an
appeal to God for a good conscience—through the resurrection of Jesus Christ, 22 who is at the right hand of God, having gone into heaven, after angels and authorities and powers had been subjected to Him.
Rom 10 says the person is saved at the point of confession "with their mouth".
8 But what does it say? “The word is near you, in your mouth and in your heart”—that is, the word of faith which we are preaching, 9 that if you confess with your mouth Jesus
as Lord, and believe in your heart that God raised Him from the dead, you will be saved; 10 for with the
heart a person believes,
resulting in righteousness, and with
the mouth he confesses,
resulting in salvation.
Salvation precedes baptism and must include confession and belief.
In a debate between R.C. Sproul and John MacArthur about baptism Sproul starts off by admitting that there is no reference in the Bible to infant baptism or baptism by sprinkling. It is only by immersion in the Bible.
Romans 6:1-6 says "buried with Him in baptism"
The Gospels say "coming up out of the water" the Spirit descended in the form of a dove.
The Gospels say "where there is much water" is where John baptized...
The Ethiopian Eunuch goes "down into the water" to be baptized.
Luke 23 has the thief on the cross saved without even being baptized at all.
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The idea that Baptists would lose their believer's baptism by full water immersion teaching on a "sola scriptura" basis is hard to show, certainly in the case of Southern Baptists.