A brother asked that question Sunday evening — a couple of verses of Scripture came immediately to mind, and more have come since that tine. I will put those thoughts down on the computer screen. I believe they give a good picture of what should characterize a true Christian, and while I acknowledge that it is not given to us to know the heart of another person yet the Bible says “By their fruits ye shall know them.”
The first sign is love, love to God and love to our fellow men. Jesus said, “By this shall all men know that ye are my disciples, if ye have love one to another.” (John 13:35) He also told us to love our neighbour as ourselves and when He was asked “Who is my neighbour?”, He told a story that had as its hero a man that the questioner would have felt duty-bound to despise. In other words, if we claim to be followers of Jesus Christ there should not be anyone whom we cannot love. And this love is the best outward evidence of our love to God.
Next would be the fruit of the Spirit. If we claim to be a child of God and to have received the Holy Spirit, then the way we live and the way we react to the people and situations we encounter should demonstrate not only love, but also joy, peace, patience, gentleness, goodness and all the other qualities mentioned. The Scriptures (Galatians 5:22-23 & Ephesians 5:9) do not speak of fruits, as though we could pick some and not the others, but of a singular fruit which has all these characteristics.
Another sign is that a Christian will not be in love with the world and the things of the world (1 John 2:15-17), nor will his way of thinking be patterned after the thinking and spirit of the times in which he lives (Romans 12:2). There should be clear evidence of submission to the will of the Lord: “Why call ye me Lord, Lord, and do not the things which I say?” (Luke 6:46)
Thus if we meet someone who appears to be on fire for the Lord and filled with joy, yet also exhibits a passionate love for the things of the world and a craving for the approval of the world, there are some legitimate questions which need to be asked.
Likewise, if we encounter someone who is very scrupulous in his avoidance of anything which could be considered worldly, yet is openly critical of all who do not live as he does, we need to enquire if there is a genuine, active, connection to God.
Would to God that all those who name the name of Christ could be truly filled with the joy of the Lord, love for everyone they meet, have no attachment to earthly things, and never be troubled by the thought that this makes them better than other people.