One of the simplest ways to know if you are a genuine child of God or not is this: do you obey Him? This would seem obvious. Yet there are many today who adamantly insist that although they do not live the life they know God wants them to, they are still believers.
There is an insidious heresy that proclaims it is possible to live in constant disobedience to Christ and yet to be heaven-bound when you die. Of course, no one is perfect. Everyone sins at times. Yet those who truly belong to Christ will have a desire within them to please God and to do what He says. When they fall short, they will feel convicted and know they are dishonoring God.
However, for those who willingly and knowingly reject God’s clear instructions day after day without any sense of conviction or remorse, it is doubtful that they have ever truly been born again. They may have prayed a prayer or signed card some time in their past, but the evidence that it “took” is missing.
If you want assurance you are a born again, child of God, you don’t have to peer back into your distant past to remember a hasty decision you made as a child. Just ask yourself the question: am I doing what I know God wants me to today?