Not all men come to a saving knowledge of Jesus, even facing certain death. Despite this painful reality, Paul urges Timothy to pray, and to exhort others to pray, that all men might recognize and accept Jesus as their Savior, who paid the steep ransom for our sin with his death, and that on a cross.
Preaching the gospel is like parenting. You bring your kids up in the “nurture and admonition of the Lord.” You teach them right from wrong. You expose them to everything you think they’ll need to survive in the world. You point them to the Lord. But you never know if it all will take, because they have a mind of their own. This fact keeps you on your knees.
This hope of salvation motivates us to share the gospel. This is why we pray for “all men” but only a few seem to benefit. This is why we hope for “all men” to accept Jesus, but we know they won’t.
Just think if Paul and Timothy were realists and backed off, because odds are, only a few would walk the aisle?
Not a chance. This hopeful attitude is “good and acceptable” in God’s sight. (1 Timothy 2:3)
At the Gate 
i believe those who survive the tribulation will be able to procreate. Those children will still have the opportunity to accept or reject, and can still sin due to the flesh without the presence of Satan.
Some will even be born during the Millennial kingdom and still reject Christ, even as he reigns physically on earth.
Very good point. I take it you mean those deceived by Satan in the brief time he is released towards the end. Those are described as numerous as “the sands on the seashore.”