Boniface [ AD 680-754], also known as the Apostle of the Germans, was a Christian missionary who spread the gospel throughout the Frankish Empire during the 8th century.
Below is the introduction to one of the fifteen sermons that remain in existence. In it, he lists abortion as one of the devilish works we are to renounce as Christians.
Listen, my brethren, and consider well what you have solemnly renounced in your baptism.
You have renounced the devil and all his works, and all his pomp. But what are the works of the devil?
They are pride, idolatry, envy, murder, calumny, lying, perjury, hatred, fornication, adultery, every kind of lewdness, theft, false witness, robbery, gluttony, drunkenness, slander, fight, malice, philters, incantations, lots, belief in witches and were-wolves, abortion, disobedience to the Master, amulets.
These and other such evil things are the works of the devil, all of which you have forsworn by your baptism, as the apostle says: Whosoever doeth such things deserves death, and shall not inherit the kingdom of heaven.
But as we believe that, by the mercy of God, you will renounce all these things, with heart and hand, in order to become fit for grace, I admonish you, my dearest brethren, to remember what you have promised Almighty God.
From a sermon on “The Renunciation of the Devil in Baptism” (Sermon XV)