Gene Veith makes a typically insightful post about the implications of the Incarnation for the politics of abortion:  

The Son of God was incarnate when, in the words of the Apostle’s Creed, He was “conceived by the Holy Ghost” and later “born of the Virgin Mary.” If the fetus becomes a human being at some later point–when the soul enters the body, or when the fetus shows brain waves, or some other point–how does that apply to the Incarnation without falling into some kind of modalism or other heresy? Anyone who confesses the Apostle’s Creed must be pro-life when it comes to abortion, embryonic stem cell research, and the rest of it.