Our first confession is made as believers before our Lord Jesus Christ to have the true salvation of our soul and we must do it from the heart since that is the most important decision and action of our lives.
The second confession is when each time we commit a sin we admit it and recognize sin in order to keep ourselves in communion with God, we must confess openly and honestly with God.
1 John 1: 9
If we confess our sins, God, who is faithful and just, will forgive us and cleanse us from all unrighteousness.
Let's take a daily time to confess to God, if you have committed any sin, confess it! Because before God we can not hide our sins, sometimes it is difficult to accept our sins but it is harder to confess them because we feel ashamed of what we have done, but it is clearly what God wants, that we confess our sins to cleanse ourselves from all evil, not only confessing is repentance of heart and away from such sin.
Acts 3:19
Therefore, in order that their sins may be erased, repent and turn to God, so that times of rest may come from the Lord.
Repentance is a very important step to separate us from sin as it means to turn away from sin, repentance brings us closer to God, and as God forgives our sins we must also forgive our neighbor.
To confess our sins means to reconcile us with God, when we do it with sincerity we are freed from sin, we must recognize our faults because God arranged it in His Holy Word.
Proverbs 28:13
He who conceals his sin never prospers; who confesses it and leaves it, finds forgiveness.