What are Christians?

Are Mormons Christians? Are Seventh Day Adventists Christians? Are Calvinists, Jehovah Witnesses, or Catholics Christians? Can we, Protestants, come off our high seat of judgment of others and begin to concern ourselves with...ourselves? These articles putting others down, reminds me of the Bible story of the Pharisee and the tax collector who both pray at the Temple (Luke 18:9-14). The whole parable is about trusting ourselves to be righteous and despising others. The tax collector was more concerned about his deeds than about the relationship he had with God. I am asking the question for which the Pharisee stated of "us" Christians. Is what makes a Christian one who attends service three times a week, tithes, and does good to those in need?
 Let us not forget the rich young ruler also, and why he wasn't going to Heaven (Mark 10:17-27). Remember, the rich young ruler respected whom Jesus was, recognized in public His authority, knew and lived by the commandments (meaning he had the right doctrine), and was well respected in the community. Yet, he wasn't a Christian.
Let's stop telling others they have a splinter in their eyes and start showing others what Christianity is by the love we have for Jesus and for others (1 Corinthians 13). From this agape love, which is love that can never be deterred, our fruit will naturally show (Matthew 7:16).
We don't become the light of the world (Matthew 5:14) by placing a basket over other people. We are the light of the world by placing that light on a stand; we are the salt of the world by adding flavor to others' lives in the name of Jesus and showing His kindness and His love. To be a Christian is not something we should have to claim by our mouths, but what others say of us because of the reflection of His image we allow to shine.
Although we should never condone what goes against God's Word, we should never stop loving another because they are lost or showing out. We are to love our enemies. God judges the love in our heart not how we treat those who are easy to love, but how we love those who are hard to love.
I could never shun a family member or friend if they were living in a way that did not glorify God. All I can do is love them and be there to catch them when they fall or encourage them when they are down.
May we only judge another by the amount of love they may need and receive, and not by how good we may think we are. A Christ-ian must have Christ-type love. That is a Christian.