Really? Well, if you meant "sin" in the sense of an carnal sin of the flesh, you should ask if anyone had bothered to tell that to King David who was God's prophet and who nevertheless sinned repeatedly in the flesh yet knew and understood Christ intimately.
I'm glad you cited David, because Paul cited him too,
Against thee, thee only, have I sinned, and done
this evil in thy sight: that thou mightest be justified when thou speakest,
and be clear when thou judgest. Psa.51:4, Rom.3:4
It's obvious Paul is teaching in Rom. 3 how people who commit sin (which we all have) aren't seeking God, yet this doesn't mean we can't repent. Psa.51 is a great prayer of repentance.
Same thing with Saul/Paul, his sin was worse - it was his mission to destroy Christianity. Even after salvation Paul referred to himself after as the "chief of sinners".
Every Christian should view himself this way, because our sins are no different from the sin of nailing God to a cross.
However, the sin which neither committed, nor does anyone who is saved ever commit, is the sin of not having an all-encompassing and total trust in Christ's offering for the forgiveness of sin and of Him as Saviour.
Please understand that "Christs' offering for the forgivness of sin" was his goodness and forbearance in not ripping the heads off vile men who tortured him.
I think the difficulty you have is that you can't fathom the size or depth of the forgiveness given to those
whom God has chosen for forgiveness: He forgives them to the uttermost before they understand or seek Christ.
Their understanding of Christ comes about from/by/after that they are forgiven.
God ordained that people who decide to repent will be forgiven,
to this
man will I look,
even to
him that is poor and of a contrite spirit, and trembleth at my word. Isa.66:2
So repentance comes first.
It's not hard to understand what you've said, it's impossible to understand because you either don't understand or you've misrepresented those verses. Where in them do you find "learned about God"? It simply is not there. Instead, they say learned "OF God", meaning that they must learn FROM/BY God; that is, that God must first teach them - that is the only way it can happen. The point is that they CANNOT learn OF God unless having been drawn BY God: they must be drawn BY God to be saved. That God does not draw everyone is evidenced by the fact that not everyone becomes saved. The "all" of v45 is of the "draw him" of v44 -- it is not for everyone ever born, if that's what you meant. He precisely tells us - using your phrase -- that He "puts a spiritual magnate on some people". How can someone love either Jesus or God if they don't know Jesus or God and only God's teaching of them can make that happen.
Those who were infuriated, were so because then as now, natural man cannot bear to hear that salvation is not within their power or choice to achieve, but only God's to give to whomsoever He may choose to. So then, why is it that you are unable to understand that?
Because you're saying God sent all the Prophets and recorded the scriptures for no reason.
And as I pointed out before, context dominates meaning. His point is, people who love him know God, which is why,
After these things Jesus walked in Galilee: for he would not walk in Jewry, because the Jews sought to kill him. Jn.7:1
(The religious leaders, not every Jew.)