Abortion is a sin. Having more children is good because there are going to be winners and losers in life. Animals have more babies for a reason, not all of then are going to be successful in life or strong enough to survive. The same applies to humans, only the strongest survive. The strongest men rise to the top and they smash the male competitors into the ground so they can pass on their gene code. Abortion is not right and why would a strong man sit idly by allow that to happen? God does not want unborn children to be killed before they had a chance, God enjoys watching the strong man fighting his way to the top in an endless cycle that has gone on since the dawn of time.
If you say it is a sin, you mean it is a sin for you. As I said religious freedom means other religions can have differing opinions. To deny that is contradictory to american values.
But you should stick to faith-based arguments, because your interpretation of science is even worse. What you argue is called by biologists r-strategy:
R-strategy basically means to produce as much offspring as possible and a few survive. But in evolution also a different strategy showed itself as very successful: K-strategy. This is the other way, produce few offspring but devote them a lot of resources so they have better chances of survival. Humans are K-strategists like a lot of bigger and more complicated animals (the costs and the losses of the r-strategy are increasing with the complexity of organisms). So the r-strategy you recommend is more suited to simpler organisms without a brain.
At the end you try to glue science and religion together. That is not very pretty. And again you attack american values by completely forcing only one religious interpretation on anyone. Many people have differing images of God. The american way is to accept and tolerate these differing views.