Although there is no verse that explicitly mentions “abortion,” there are many that would designate it a sin. Of course, there is the general injunction against taking the life of a human:
• “Whoever sheds human blood, by humans shall their blood be shed; for in the image of God has God made mankind. (Genesis. 9:6)
The Bible makes no distinction between the human pre-born and the human post-born. A human is a human and not an animal. There is therefore no reason why this prohibition wouldn’t also apply to humans in the womb:
• "Do not pollute the land where you are. Bloodshed pollutes the land, and atonement cannot be made for the land on which blood has been shed, except by the blood of the one who shed it.” (Numbers 35:33; Gen. 1:26-27)
The next verse identifies what happens when a pre-born is killed:
• "If men who are fighting hit a pregnant woman and she gives birth prematurely but there is no serious injury [to the fetus], the offender must be fined whatever the woman's husband demands and the court allows. But if there is serious injury [to the fetus], you are to take life for life.” (Exodus 21:22-23)
If there is serious injury to the fetus, the penalties seem to be the same as the penalties for injury to a post-born. If the pre-born dies, there is to be a life for a life. Clearly, the pre-born is regarded as a human life in the same way the post-born is.
We also observe that God has profound interest in the fetus, as He does with any human:
• For you created my inmost being; you knit me together in my mother's womb. I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well. (Psalm 139:13-14)
God tells his Prophet Jeremiah that even in the womb, he was a “you” not an “it”:
• "Before I formed you in the womb I knew you, before you were born I set you apart; I appointed you as a prophet to the nations." (Jeremiah 1:5)
Even in the womb, the pre-born is considered a “baby”:
• As soon as the sound of your greeting reached my ears, the baby in my womb leaped for joy. (Luke 1:44)
The baby is God’s workmanship:
• “Did not he who made me in the womb make them? Did not the same one form us both within our mothers?” (Job 31:15)
Abortion was explicitly condemned by the early church:
• “Love your neighbor as yourself…You shall not murder a child by abortion nor shall you kill a newborn.” (Didache)
• “You shall love your neighbor more than your own life. You shall not murder a child by abortion nor shall you kill a newborn.” (Barnabus)
• [In a vision of Hell] “I saw…women…who produced children out of wedlock and who procured abortions.” (Apocalypse of Peter)
In fact, there exists no Biblical evidence that we should not regard the fetus as a human being created in the image of God.
If you have had an abortion, confess your sin to the Lord, and He will forgive and cleanse you of your sins (1 John 1:9) that you might find the healing you will never find by trying to convince yourself that you did what was right.