I'm pretty sure there are people in the world who haven't heard of Jesus.
I'm pretty sure God can reach them...
Romans 8:28-30:
And we know that in all things God works for the good of those who love him,
who have been called according to his purpose. For those God foreknew he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers and sisters.
And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.
So then, both hearing the Word and salvation itself is all according to God's will and purpose.
Parents may not have seen fit to pass down the teachings of Jesus to their children as the were commanded and so we still evangelize to the next generations...
Psalm 78:1-8:
My people, hear my teaching;
listen to the words of my mouth.
I will open my mouth with a parable;
I will utter hidden things, things from of old—
things we have heard and known,
things our ancestors have told us.
We will not hide them from their descendants;
we will tell the next generation
the praiseworthy deeds of the Lord,
his power, and the wonders he has done.
He decreed statutes for Jacob
and established the law in Israel,
which he commanded our ancestors
to teach their children,
so the next generation would know them,
even the children yet to be born,
and they in turn would tell their children.
Then they would put their trust in God
and would not forget his deeds
but would keep his commands.
They would not be like their ancestors—
a stubborn and rebellious generation,
whose hearts were not loyal to God,
whose spirits were not faithful to him.
And yes, the Word about Jesus was declared to the ends of the earth at the time of His ascension...
Colossians 1:21-23:
Once you were alienated from God and were enemies in your minds because of your evil behavior. But now he has reconciled you by Christ’s physical body through death to present you holy in his sight, without blemish and free from accusation— if you continue in your faith, established and firm, and do not move from the hope held out in the gospel.
This is the gospel that you heard and that has been proclaimed to every creature under heaven, and of which I, Paul, have become a servant.