Eternal sin
In Catholic teaching there are six sins that blaspheme against the Holy Spirit. They are: Several passages in the Bible are frequently interpreted as referring to the unforgivable sin:
Penance
Essential to the sacrament are acts both by the sinner (examination of conscience, contrition with a determination not to sin again, confession to a priest, and performance of some act to repair the damage caused by sin) and by the priest (determination of the act of reparation to be performed and absolution). among the penitent's acts contrition holds first place. Serious sins (mortal sins) must be confessed within at most a year and always before receiving Holy Communion, while confession of venial sins also is recommended.