Agreed. As with so many things, the solution is to restrict christo-fascist speech and put out pro-abortion propaganda, but we can't do that without power. For the moment, the best you can do is get them to shut up by exerting social pressure. Stuff like cutting anti-abortion family members from your life etc. A cousin really pissed off one of my aunts when she wasn't invited to his wedding.

Edit: Also obviously direct action to assist abortion seekers/providers etc, the above is specifically on the subject of convincing someone.