ALL Scripture is inspired not just the New. There is no other name than Jesus by which people are saved. Those in the Old were saved by the grace Jesus merited for us by his sacrifice just as we are.
Just as they could choose God, we can choose God.
Every man can seek God and find him.
"And as he made from one man every nation of mankind to live on all the face of the earth, having determined allotted periods and the boundaries of their dwelling place,that they should seek God, and perhaps feel their way toward him and find him" Acts 17:26-27
Genesis 12:1 Now the LORD had said unto Abram, Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee:
This is the first mention of the LORD and Abram together in a sentence.
God seeks everyone. He desires that no man perish. When God first spoke to Abram he didn't say
, "who is this? " He already knew who God was. He also freely chose to obey. Apparently Abram was not totally depraved and unable to respond to God's call.
It doesn't matter what Abram thought. There is only One God and Abram was worshiping that One God just like the Jews, who deny the Trinity, are still worshiping the One God.
Abram was not depraved and incapable of responding freely to the call of God.
John 4:23 But the hour cometh, and now is, when the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him.
1 John 2:23 Whoever denies the Son does not have the Father either; he who acknowledges the Son has the Father also.
You also have to take into account Romans 2: 14-15 where Scripture says that if the Gentiles (which also refers to pagan nations) do what the law, that is written on their heart, requires they may or may not be excused on their day of judgment.
ἔθνος éthnos, eth'-nos; probably from G1486; a race (as of the same habit), i.e. a tribe; specially, a foreign (non-Jewish) one (usually, by implication, pagan):—Gentile, heathen, nation, people.
Someone who through no fault of their own does not know Christ or has a distorted understanding of who He is can also be saved. That is God's call. God is not a moral monster who will condemn the innocent.
This is why private interpretation of Scripture is not biblical. Scripture alone is a false teaching. It is the mark of a cult who think they can pick up an infallible book inspired by God and come to an infallible interpretation apart from the very Church that Christ Himself established for that purpose, so that we would not be like children tossed to and fro by every wind of doctrine brought forth by men.
It's also a straw man, as we do not believe in "scripture alone". "Sola scriptura" refers to the supremacy of scripture over other sources, not to scripture being the only source.
That's the difference between "sola scriptura" and solo scriptura.