You can't have a universally consistent argument against abortion without the Biblical Christian worldview.
You can have an argument, but it will necessarily have a fundamental flaw when taken to a logical or ultimate conclusion, or, if presented against a conflicting worldview.
It's because of this belief I am convinced our best and most powerful arguments, tactics, and plans will not be those which avoid, pay lip service to, assume neutrality, or secretly be ashamed of the Biblical Christian worldview, but those that intentionally and deliberately presuppose it as the foundation.
God is the beginning of all knowledge and wisdom and in Christ are all the treasures of knowledge stored. To seek a solution apart from the source is to deliberately choose a path which will necessarily always come short.
God says the killing of a preborn child with malice aforethought is a capital crime. That's our objective starting point. Our unshakeable ground. Our unmoveable standard.
We begin with and do not back down from: "God said."