Many non-Christians but, surprisingly many Christians too, make an assumption I think is false: God's purpose in giving life is just about people getting to heaven. In other words, God is just trying to get back as many of the souls He gave out as He can. Already starting to sound a little strange, isn't it?
I think saving souls is certainly important, but that is NOT the most important thing. Simply put, the purpose of life is not death. The purpose of life is to glorify God and we do so both by making wise choices to acknowledge Him and obey Him but also those who make bad choices end up glorifying God and showing His wisdom and His judgment. Look at Pharaoh.
Here is a sample pro-abortion argument where this misunderstanding comes into play.