From the letters of the Venerable elder Leo of Optina.
We will not be afraid if we have to struggle after the confession
We will not be afraid, if we have to struggle after the confession, it is better to deal with bodily impurities than with pride, and although we fall in the battle, we should not leave the battle field: then we have much more need for a doctor.
Fear of God force us to confess sins
You are worried most of all and you reproach yourself that you care more about pleasing the mentors than God, that the thought that you should confess every sin to me holds you back more than the fear of angering the Lord. These thoughts lead you to self-assurance. Don’t you do this because of fear of God, when you repent of your sins before God, having as a witness His servant, who was entrusted the keys to bind and loose. St. John Climacus in the 4th step writes: “By resolving to make one’s confession, the soul is thereby held from sinning as by a bridle; for we do not confess our crimes to henceforth shamelessly repeat the manifested ulcers, as if in the darkness, not to make them set on the bitter, but healed, this opinion is contrary to yours.” Therefore, you clean yourself of passions and sins, you do not lose anything, but you gain piety and peace of conscience, not thinking that by yourself, but by the prayers of others you received this, while many who walked the high path fell with a great fall. Think, do you refrain from sins fearing me? I'm not a reader of the heart. If you hide anything from me, I will not call you to account and denounce you, and you have nothing to fear from me. From this you see that the fear of God compels you to confess your sins, and, consequently, to refrain from them, and not the fear of me. You see yourself prone to arrogance – try to reject self-assurance as much as possible, and rejecting this thought that disturbs you completely, please be peaceful and calm.
The Holy Fathers commanded those new in the faith to generally confess all their sins from their youth
But in order for you to foresee faults and to protect yourself and those who follow your wise admonition, you deign to ask our wickedness with a true sincerity about the previous bad impulses; although they were confessed to confessors, the burden of conscience is not alleviated, but you are burdened and embarrassed, i.e. you are not contented as you should, and it is evident that the confessor, who confessed you, was not very skillful. And therefore the holy spirit-bearing fathers commanded those new in the faith and wishing to adopt the monastic angelic life to confess all their sins in general from youth and, thus, purify their conscience and soul, and lay a new foundation, i.e. having cleansed themselves and relieved from such a burden, easily accept the obedience. - So I, sinful, advise your love to ask and pray to the Most Merciful Lord and God, so that by His providence He would send you such a spiritual father, to whom you could confess all your sins from youth to this age and who could instill in you the importance of them. Although we are now unable to satisfy them with penance, at least we must satisfy with repentance and tears, so that we will propitiate the Merciful Lord to relieve us from the burden and grant us courage and strength to resist the universal enemy, the devil. When the Lord, in response to your faith and diligence, grants you such a spiritual father and you do as written above, then you will see peace within your soul, and joy of the heart, and tenderness, comforting you with invaluable comfort.