Summarize this article in one sentence.
Never interrupt, shout over, or insult another person (even if you feel that they really, really deserve it).  Keep in mind that not every pro-lifer is motivated by the desire to slut-shame and control women. Some of them have never been exposed much to other ideas. Some haven't thought through the implications of taking away someone's bodily autonomy. Others had a bad life experience related to abortion, and reacted by condemning all abortion. There are reasons besides cruelty, so don't leap to judgment. Religion and government are separate, and religion and abortion rights are separate. Condemning someone's entire religion is cruel and divisive.  Not all religious people are anti-choice; for example, it is possible for some self identified Christians to be pro-choice. Even if the person in front of you is a flaming bigot, think of the nice religious people, and don't insult their religion. Pro-choice people have long pointed out how "baby" and "unborn child" are manipulative ways to refer to an unwanted fetus. But calling all fetuses "clumps of cells" is also an insensitive use of rhetoric, because there are some fetuses that are truly loved and wanted, and to those parents the fetus is far more special. Stick with the factual term fetus. Dismissing fetuses as mere "clumps of cells" can be deeply upsetting to people who miscarried a loved, wanted fetus. Don't accidentally minimize the hardship of losing a beloved fetus. Transgender men, nonbinary people, and some intersex people of any gender can also get pregnant. Be sure not to step on the toes of transgender people as you fight for the rights of everyone with a uterus. The lives of disabled people aren't automatically worth less than the lives on non-disabled people. While some "fetal abnormalities" are indeed lethal and may require an abortion to save the pregnant person's life, others (like Down syndrome) aren't awful. Be cautious about advocating selective abortion for disabled fetuses, because this can be hurtful to people with disabilities and their families.  If a person only wants to be pregnant if their future baby is non-disabled, that says something about their attitudes towards disabled people. (If they don't think they could handle a needy child, then they probably aren't ready to be parents: there's no way to guarantee that a child won't be disabled, or need a lot of help.) Aborting fetuses with disabilities isn't automatically more "compassionate." Disabled people can experience joy, and bring it to other people too. Non-disabled people experience suffering sometimes. Disability status doesn't predestine someone for happiness or sadness. Instead of lumping in disabled people with phrases like "fetal abnormalities," try using phrases like "fetuses that aren't viable," to specifically refer to fetuses that cannot survive. You are not obligated to change anyone's mind, nor do you have to keep talking to someone who says very rude or upsetting things. This may be personally upsetting to you. Say "I don't want to talk about this anymore," "I need a break," or "I need to get some air" if you can't keep calm. Any decent person will respect your wishes.  If the person makes you feel unsafe, leave right away. Call police if you are being threatened or stalked.
Be polite and courteous when defending your beliefs. Never insult someone else's religion. Don't manipulate rhetoric. Remember that not all pregnant people are women. Be respectful of people with disabilities and their lives. Take a break if you need to.