A quote from Tim Keller’s book, Center Church, p. 30:
The gospel is news about what has been done by Jesus Christ to put right our relationship with God. Becoming a Christian is about change of status. First John 3:14 (emphasis added) states that “we have passed from death to life,” not we are passing from death to life. You are either in Christ or you are not; you are either pardoned and accepted or you are not; you either have eternal life or you don’t. This is why Dr. Martyn Lloyd-Jones often used a diagnostic question to determine a person’s spiritual understanding and condition. He would ask, “Are you now ready to say that you are a Christian?” He recounts that over the years, whenever he would ask the question, people would often hesitate and then say, “I don’t feel that I am good enough.” To that, he gives this response:
At once I know that… they are still thinking in terms of themselves; their idea still is that they have to make themselves good enough to be a Christian… It sounds very modest but it is the lie of the devil, it is a denial of faith… you will never be good enough; nobody has ever been good enough. The essence of the Christian salvation is to say that He is good enough and that I am in Him!