Some type of honest and sincere repentance is necessary for any type of authentic growth and maturity. Unless we are happy wallowing in immaturity and superficiality, we come to the realization that the way we havec been doing things is not the best or the healthiest. There is not a human being alive who has not acted foolishly or erratically at the cost of almost losing a treasured relationship.
Why did I act that way? is a question we often ponder after some reflection and enlightenment. Faith works the same way.
Stumbling through life and bumping up against meaninglessness, we can begin to see that something significant is missing. We see that there is merit to a relationship with God and an embrace of faith. Before these can take root, sincere sorrow for past wrongdoing, missed opportunities, errors in judgement, and shortsightedness is necessary.
Repentance is necessary. Then having realized that we were walking in darkness, we can rejoice that by God's grace we now see the light.