2. about the mass you haven't a clue as to what the mass is all about. first we don't go to get rid of sin, that is what the sacrament of confession is for.
The 3rd Commandment says "remember to keep the Lord's day", well actually it says Sabbath but you get the meaning.
the Mass was instituted by guess who? Jesus at the Last Supper before His crucifixion. The last supper was the first mass
when we celebrate mass we re-present Jesus' great act of love for us on the cross
when we partake of the bread and wine after the transubstantiation the Body and Blood we do as Christ asked, that we "do this in memory of Him"
Jesus gave the church authority, as he said to Peter "on this rock i will build my church" etc.
we do offer thanksgiving for the forgiveness of our sins, by offering the Body and Blood of Christ to his Father in an unbloody manner. yes our sins are forgiven, they are immediately forgiven if we at the moment commited ask forgiveness and have true remorse. but we do not go to mass to ask to be forgiven we go for thankgiving. there is a difference in there if you can see it.
and lastly, although there are many more reasons, mass can if we let it change us for the better. can bring peace, spiritual strength and so forth. ok
thank you, God Bless you