Since moral law is written on the heart of every man (CCC 1860, Romans 2:15), is it possible for a protestant adult (that has crossed the age of reason) to a break moral law without full knowledge?
1860 Unintentional ignorance can diminish or even remove the imputability of a grave offense. **But no one is deemed to be ignorant of the principles of the moral law, which are written in the conscience of every man. **The promptings of feelings and passions can also diminish the voluntary and free character of the offense, as can external pressures or pathological disorders. Sin committed through malice, by deliberate choice of evil, is the gravest.