Is it your belief, Paul first had to teach the Old Testament to the Gentiles before he was able to Preach Salvation to them?
That is milk of the faith, basic things that everyone can grasp, but there's more to the walk and faith than that. Even that concept, regarding salvation, there's so much more to it than just that, that can only be understood after you understand the old testament. He didn't just die for us to be forgiven of our sins, that's
one reason He had to die, but the other equally important reasons can't even begun to be grasped without understanding the old testament.
Act 17:22,23
22) Then Paul stood in the midst of Mars' hill, and said, Ye men of Athens, I perceive that in all things ye are too superstitious.
23) For as I passed by, and beheld your devotions, I found an altar with this inscription, TO THE UNKNOWN GOD. Whom therefore ye ignorantly worship, him declare I unto you.
I am not discounting the Old Testament, but it is not needed in order for someone to Preach a Salvation message to nonbelievers, and have them Believe.
It is if you plan to reach the Jews with this message. It is if you plan to reach certain people groups. And it still is, if you plan to preach this message to non-believers. See, you say it's not needed, yet the apostle to the gentiles, was Paul, the one who knew the
most about the old testament. He even constantly quoted from the old testament all throughout his writings, and even desired to explain the old testament concepts to those he converted. He literally only had the old testament to share the gospel with them, and he converted more than 3000 people. So, if you say it's not needed, I'd say I just plain disagree.
Even that verse in matthew 11:5, it's a quote from the old testament. You can't understand most of what Jesus talks about without a solid grasp of the old testament, because He is only teaching and talking about what is in the old testament. That story of Him telling the adulterous woman "go and sin no more". He wasn't saying, "ye without sin cast the first rock", as in "you've all sinned, therefore you can't judge her", He was just following God's law written in the first five books of the old testament. In order for someone to be stoned for adultery, both the male and the woman that committed adultery had to be present,
and the one who saw the adultery was to be the first one to cast the stone. The pharisees never brought the man, they only had the woman, so even if she truly had committed adultery, they couldn't of stoned her without the man. That, and they were trying to get
Him to stone her, which, because He didn't witness it, it was against what the old testament teaches. He wasn't saying, you've all sinned, don't judge her, He was saying, as it is according to the old testament, so it shall be done. Which ever one of you is doing this process according to scripture, then do it. But, He knew that they weren't following the scripture, but that they were trying to trick Him to transgress what scripture teaches, which He didn't. Little things like that, that can't be understood without understanding the old testament.
Or like in Romans 7, where Paul straight up says that he's only talking to those that know the law, because the concept he brings up next, can only be understood if you have a solid grasp on what God's law says (which is found in the first five books of the old testament). If we don't understand these things, as Peter says in 2 Peter 3:16, we will twist the truth and cause ourselves to fall into the error of lawlessness, because we are ignorant to the scriptures and are unlearned in the scriptures. Christianity teaches He told that woman to go and sin no more, and that He told the pharisees, "he without sin shall cast the first stone" because He was saying none of you shall judge anyone, but that isn't so when you have a solid understanding of the old testament. You see that the pharisees were trying to trap Him in the act of breaking scripture, but that because He knew the scripture well, He saw that, and corrected them.
Mat. 11:5
The blind receive their sight, and the lame walk, the lepers are cleansed, and the deaf hear, the dead are raised up, and the poor have the gospel preached to them.
Mat. 24:14
And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.
Mar. 16:15,16
15) And he said unto them, Go ye into all the world, and preach the gospel to every creature.
16)
He that believeth and is baptized shall be saved; but he that believeth not shall be damned.