I'm a Christian. We hear people say it, declare, and profess it all the time. How do you know they really are a Christian? If you asked those who are not, some might say it means no drinking alcoholic beverages, no cussing, and no clubbing. While you're at it, add no thinking (of your own), no smiling, and no fun. Ask a believer and they might say it means following Christ. It means to believe in Jesus as Lord and Savior; taking up your cross daily and following Jesus; being baptized; doing unto others as we would have them do unto us; helping those in need; or belonging to a Christian church.
It goes without saying that in order to be a Christian, we have to believe in Him as Lord and Savior so for the most part, these fit perfectly with three of the definitions Dictionary.com lists for the noun form of the word. But the one that resonated most with me is “a person who exemplifies in his or her life the teachings of Christ”. How is that done? We do this by being His disciples and studying His life.
Paul wrote that we should imitate God in the love that Christ showed for us (Ephesians 5:1-2). Jesus exuded perfect love in His life and in His death.
In 1 Corinthians 13, Paul lists the characteristics of love and each one with the others creates a perfect picture of Christ's love. He demonstrated what love looks like the night He washed the feet of the twelve. He ultimately demonstrated his love for them and all of humanity in his death (1John 3:16). As imitators of Him, we should be able to extend this same love to other believers (John 13:35), to other parts of the body, regardless of race or denomination. If the church loved in that way, how much good could be done in Christ's name among those who do not believe? How many souls might come to know Him as a result of the evidence of such love? How many fewer instances might there be of us wondering if someone really is a Christian?