Everyone makes mistakes. No matter how hard you try, you are going to screw up.
But there are two things you can do - two decisions you can make that will keep your mess up's from messing up your life.
First, do not ever engage in deception. Never try to make things appear to be different from what they are. There is nothing evil about screwing up. But slight of hand is evil.
Second, when you realize you have made a mistake, move quickly to admit it and make amends. This includes asking for forgiveness and forgiving yourself.
These two steps will prevent mistakes from becoming disasters.