Secret and presumptuous sins
Psalm 19:12-13 Who can understand his errors? cleanse thou me from secret faults.
13 Keep back thy servant also from presumptuous sins; let them not have dominion over me: then shall I be upright, and I shall be innocent from the great transgression.
Secret sins:
When we think of secret sins we think of something we try to hide or keep from open and public scrutiny. But here David pleads to be kept back from secret sins; he is meaning sins that he is not aware of that he is committing. God spoke of this in Lev 4:13-14. David knew that he was human and affected by the original sin and fallenness of humanity and as such \, he was unable to know all the applications of God’s law and there may be times that he would sin against God in disobeying His command; his desire is to be and stay in right relationship with God. We are not able to hide anything from God (Prov 9:17-18; Jer 23:24; Ro 2:16; 2 Sam 12:12). God sees and knows all and there is nothing we can hide from Him. We are told to hide some things from other people, however (Matt 6:17-18).
Secret sins may also be of a nature that pertains to our fallen humanity and wrong thinking and reasoning. Sometimes we do things that we should not, say things we should not or even not say or do somethings we should because of our humanity that has been affected by the fall.
Presumptuous sins:
Presumptuous sins are of a different nature and origin. While they also originate from the fallen nature they are sins that people do in spite of their knowledge of God’s law and what they know to be right. Presumptuous means self-willed; arrogant, proud. Those who presume upon God‘s grace that He will forgive even though they are committing sin shall be judged by God but also by their sin they presently are committing. The writer of Hebrews speaks some about this type of sin (Heb 10:26-27). Hebrews also speaks of those who fall away perhaps by presumptuous sins and their coming back to God (He 6:4-6). Presuming can also come in the form of disobeying and then trying to be righted with God by delayed obedience (Num 14:40-45).
Secret sins will plague us throughout this life, but we can avoid the presumptuous sins by allowing God to cleanse us from within and then staying close to Him through prayer and obedience