We must still expose our dark deeds to the light and allow them to be transformed, because unconfessed past sins can skew our present behavior and our relationship with God. Or, to use other terminology, we should constantly be digging into our souls, bringing things to light. If we come across a sin buried somewhere, we should expose it to the light, confessing it and repenting of it. Living a life in harmony with our spiritual reality is admittedly difficult. We live in evil days.
People do evil routinely.
Sometimes they even regret what they are doing, but they do it anyway on the grounds that it is general practice, and if they do not participate they will be in some way disadvantaged. We can afford to suffer a setback from right behavior, because we know that our eternal gain will far outweigh it. Professed Christians who refuse to sacrifice a momentary advantage to gain an eternal advantage cannot be placing much stock in what Jesus says. My theory is that people who say they trust Jesus for heaven but live in severe anxiety about their present circumstances are deceiving themselves. Therefore, be children of the light, not children of darkness.