Sin is unlawfulness, God loves sinners but hates all forms of sins. Sins can be made by words, thoughts or deeds. Venial sins are sins of lesser importance, sins that do not have grave consequences. Venial sins can weaken your will power and on account of venial sins a person can have to stay in purgatory for a periode of time after dying, before enjoying eternal happiness, to be purified. Mortal sins is of grave matter and make's you loose the grace you have received, it also makes you loose your right to be a member of God"s family. Original sins is the sin commited by our first parents Adam and Eve, actual sins are our personal sins. The only unforgivable sin is blasphemy against the Holy Ghost, such as a grave offence to God's crown, such as refusal of the lord's mercy and forgivness, such as, impenitence.