Will all those who have not committed the unpardonable sin of rejecting Jesus go to Heaven?

I have heard it from various people, preachers, and what-not that the Unpardonable sin is rejecting Jesus over and over until you have killed your ability to accept him from that point forward. Is that true?

I speak from partial ignorance because while I know Jesus is the only way to get to Heaven I am confused why people would end up in Hell if they haven't rejected Jesus. Along time ago I used to believe that God the Father made the universe, and so I incorrectly reasoned that that people could go to Heaven without accepting The Son.

On the other hand, now that I know better, and that Jesus created the world and everything in it, and all things, how is it possible that people have not ever understood that God made the world and everything in it?

God is the designer. Since God the Son is the Designer of the world, is it possible that people could have died without knowing that Jesus made the world and thus he wasn't the Son of God, and the Saviour of the World?

I made many mistakes regarding this extremely important issue, and yet I have been reading the Bible frequently.

In the Old Testament, God does not condemn children of cursed people's because they are unable to choose Good from Evil. The problem I have is that if God does not condemn Children for their sins, or the sins of the others, why would he therefore condemn others for being ******** of Jesus'es sacrifice and death on the Cross?

Yes, I've heard it often, God made the world and everyone who has been in the same world shouldn't have an excuse because he made the world. But, what I forget, since I haven't read that particular verse in the Bible for a long time, is that, was that talking about Salvation or just knowing that God is there, and thus being in trouble for his Wrath?