When you were a child, did you ever do something that you were afraid to tell your parents? Something like break a window? As a kid, were you ever afraid to show your parents your report card? Have you ever decided not to do a chore, and then hide it from your parents? All of us have probably done something like this at some time or another.
Why did we not want our parents to find out about our wrongdoing? Why did we not want to face them? The answer is simple, because if we brought this to our parents, we would have been ashamed. We knew we could have done better or should have done something different, but we did not do it.
John the apostle is here making a similar analogy. John encourages the readers of his epistle to remain in Christ. He encourages them to imitate Christ and to obey Him. He encourages his readers to live a life of obedience to Christ and love for God and neighbor. Here, John tells us why it is important that we live this way.
We should not live the same lifestyle that the world lives because, when Jesus returns, those who have lived such a lifestyle will be ashamed. When confronted with the holiness of God, we see how terrible sin really is. Those who live a lifestyle of obedience to Christ and love for God and neighbor will not be ashamed when Jesus returns. There is no reason to be ashamed of hearing, "Well done!"