“A soul does not benefit from the Sacrament of Confession if it is not humble. Pride keeps it in darkness. The soul neither knows how, nor is it willing, to probe with precision the depths of its own misery. It puts on a mask and avoids everything that might bring it recovery.” –Saint Faustina
All sins that you confess will be forgiven by Christ through the priest in Confession. But if you intentionally hide a sin because of your pride or embarrassment, that sin stays on your soul. If you don’t tell your doctor about a particular pain in your body, he will not prescribe the proper medication. Don’t hold anything back in Confession! Christ wants to heal all of your wounds!