Have you ever heard of the term, “Naturalism.” It is one of the most popular ideologies today. According to Christian philosopher Ronald Nash in Life’s Ultimate Questions, it is the view that “nothing exists outside the material, mechanistic (that is, nonpurposeful), natural order.” Most naturalists are physicalists who believe that “everything that exists can be reduced to physical or material entities.” In other words, the “physical universe is the sum total of all that is.” By definition, naturalism as a philosophy rules out the existence of God, angels, demons, an immaterial soul, the afterlife, and any respectable notion of free will.
By the way, the book mentioned above is a splendid introduction to philosophy from a Christian perspective (evangelical / Reformed to be more specific).
Psalms 10:4 names an interesting characteristic of sinful pride: “in all his thoughts there is no room for God” (NIV).
Tim Challies posted a YouTube link about abortion in his daily blog today that might be helpful. While it is not a philosophical treatise against abortion, it is a five-minute video that you might find helpful as a Christian, especially in light of what is being decided in the Supreme Court.