The main cover up is people think that they are good people and have not done anything wrong. There is no such thing. We are born into a sinful world...we are sinful people. Even Jesus said to suffer the little children to come unto Me, and forbid them not: for of such is the kingdom of God. Verily I say unto you, Whosoever shall not receive the kingdom of God as a little child, he shall not enter therein. And He took them up in His arms, put His hands upon them, and blessed them. Mark 10:14-16
Sin even affect little children as well as you and I. As long as you live in this world you will be surrounded and affected by sin of some sort. That is why christians are said to be in the world...but not of the world. That is because they accept the saving grace of Jesus. Not that they are perfect or sinless because of their own works....but because of what Jesus did on the cross. Any good works that you may do as a christian are due to your mind being renewed in Christ.
Christians are to strive to have the mind of Christ so they make better decisions for their own selves and to make a better footprint in this world...however, christians still stumble and fall due to their own sins and the deceptive sins of the world. We fail in the sense that we are human, but it's by God's grace that we have asked Jesus to cleanse us of all sin, which makes us acceptable and righteous in His eyes. We all struggle in this world, but a heavenly kingdom is coming where the struggle will be over.