Sir,
At first, I wasn't even going to respond to your ridiculous Facebook comment, since that would give you more visibility, but then I decided that responding may be a good opportunity to educate you (and the many like you), so here we are.
I'll start with the basics: as Christ-followers, we are first citizens of Heaven, not earth. Our identity is grounded in Christ before it is found in our nationality or political ideology. That means that even though you may love our president and I think he has areas that need improvement, if you and I have both been re-born through Christ's sacrifice, we're siblings. For that reason, I called you a "man" and addressed you as "sir" despite the fact that you acted like an internet troll. If you're not covered in Jesus, then I have an even greater responsibility to show you the love of Christ through how I treat you, so I will continue to address you as sir.
Second, people of the same religious beliefs can have different political beliefs. Christians are not carbon-copies of one another, although we are all supposed to copy Christ. Christ valued the poor, the oppressed, and the outcast through His many miracles and who He chose as followers. The Bible clearly states the value of the unborn in Psalm 139:13-14. Jesus paid taxes (Matthew 17:27). Romans 13 tells us to obey the laws of the land, for God places government. Paul reminds us in Philippians that we are citizens of Heaven. And so, as citizens of Heaven who are called to obey our current government, sometimes we vote differently.
Some Christians think that Democrats are better at valuing the poor, the oppressed, and the outcast. Yes, that means that they're voting for a party that is pro-choice instead of pro-life. That is a sacrifice they have to make and will have to stand before God for. The Christians who vote for Republican candidates will have to stand before God for the way their party has responded to refugees and immigrants, although Republicans do value pre-birth life in a way that honors God.
You, sir, clearly favor the Republican side, given that you support the Republican president, and I think that's okay. Republicans are not evil for the values they have. But if you want that grace given to you, you must extend it to the Democrats as well. Grace isn't one-sided. Jesus brought grace for everyone; no one was exempt.
There was grace for the Pharisees like Nicodemus and for the prostitute who washed Jesus's feet with her hair and tears. Pharisees and prostitutes had different values and different sins, but they were made equal under God's grace through the sacrifice of Jesus. That's how you need to look at the people who agree with you and those who are on the other side of the political aisle from you: equal under grace.
Lastly, you need to stop acting like a troll. Making claims on other people's salvation and religious beliefs based on political beliefs doesn't help anyone. It makes you look like a jerk. It doesn't influence anyone's religious or political beliefs. At the end of the day, you and others will leave the social media comments section annoyed and frustrated.
If you want to act like a Christian you're claiming others aren't based on political beliefs, then you need to love. Jesus told the disciples that Christians would be set apart and known by our love. Your comment was the furthest thing from loving.
This is the point in the letter where I'm supposed to tell you I've forgiven you because of the Holy Spirit's work in my heart, but I don't have that ending yet. I'm still working through my anger that a stranger on the internet could make such a rude, hurtful comment with so little thought. You deserve that honesty. Thankfully, though, this letter doesn't end there. Although I haven't forgiven you yet, I am working towards that goal through prayer. Someday, I will be able to say that I not only forgive you but love you, because God loves you and I'm supposed to live like Him.
"The Lord bless you and keep you; the Lord make his face shine on you and be gracious to you; the Lord turn his face toward you and give you peace." (Numbers 6:24-26)