A Christian is somebody who has heard the gospel, somebody who believes in the Son of God and that he died and rose again. They have put their total trust in Jesus. They believe that his death brings forgiveness and adoption into his family.
Ephesians 2 v 8-9 says that Christians are saved by grace. Salvation is not a reward for good things. However as a Christian we should still seek to do good things.
The evidence of being a Christian is having a changed life. Christians are the light of the world and we have to let Gods light shine out in the world. We are to bring good into the world and preserve the good things of the world like salt.
Coming to church does not make us a Christian and neither does singing or reading the bible. However, these things are essential to the Christian life. Having Christian parents or being christened doesn't make us a Christian either. The only thing that makes us a Christian is believing in him, his death on the cross and forgiveness of sins. We must believe in his resurrection and repent of our sins.
In the bible Jesus says come and follow me. The disciples sat and listened to his teaching and so should we. We should listen, obey and let our light shine. Nobody can ever take away the eternal life given to the Christian.
The best decision we can make is to come to Jesus. Don't miss out, come to him, believe he died for your sins and accept him as your Saviour.
John 3