One of my skeptical friends who hangs around Christians a lot posted the following: “HERE’S A THOUGHT: Maybe you wouldn’t have to say you are a Christian all the time if you would just act like one most of the time. Ya think?”
This sort of exhortation among Christians to show they are Christians by what they do rather than by what they say is rather pompously prejudiced in favor of Christianity, even as it attempts to be a dig at Christians who are “all talk and no action”. Because what are these behaviors that are supposed to “tell people you’re a Christian”? Is it giving to the poor? How would that tell anyone you’re a Christian? Are you implying that only Christians give to the poor?
Is it forgiving people? Refusing to judge people? Sacrificing for others? Being compassionate? Being gracious? Showing humility? Loving others? Doing unto others as you would have done unto you?
Which of these things are so uniquely Christian that when people see you doing them they should assume you must be a Christian? Which of these valuable things are you implying that Jews, Muslims, Hindus, pagans, and atheists characteristically don’t do?
Because people from all faiths and none exhibit all these virtues. Christianity does not have a lock on them or on any other virtues. The only people who would assume that those behaviors are signifiers of Christianity and not of general moral decency are people prejudiced to assume that only Christians can be good people. When Christians say that a Christian should be recognized by what she does rather than what she says, they’re implicitly assuming Christianity has a unique lock on moral goodness. It’s obnoxious and false. And atheists shouldn’t be encouraging that attitude by repeating such expressions.
When it comes right down to it the only way to show people you’re a Christian is with distinctively religious Christian words, signs, symbols, ritual behaviors, and deeds. And church attendance. Lots and lots of church attendance. Especially church attendance when poseurs would never show up. And proselytize. Do lots of that. Also go out of your way to bring up Jesus in contexts that no one but a Christian could possibly want to hear about him. (Or in ways that drive even other Christians crazy.) And create conflict and alienation with your friends and family and colleagues who don’t believe by taking their non-belief as inherently offensive and any criticisms they level at your faith as personal attacks. Also try to get Christianity established as an official religion in your country, demand laws be based on Christian teachings, and get Christian theology into science textbooks.
If you really really want to prove you’re a Christian, be really really religiously Christian and go out of your way to be as public about your being a Christian as you can. Claim every sphere of life for Jesus. Do these things and everyone will get the point that you’re a Christian.
But just being moral? Loving others? Refusing to judge others? Tolerating others who are different than you or believe differently? Taking care of the poor? Doing unto others as you would have done unto you?
There’s nothing distinctively Christian about any of that.