The thing that separates us [from Protestants], though, is Sacraments. The Catholic Church, Eastern Orthodox, and Greek Orthodox Churches all have Sacraments. Each of them found in the Bible in one way or another.
Baptism of babies is there, as when the Apostles went and baptised whole homes at once, they did not differentiate age, and Christ said “bring all of your children to me.” Not just your 7 year olds on up.
Then there is Confession, where people went up to Christ to ask forgiveness, and He does forgive them, and Christ tells the Apostles, “What you bind on earth is bound in heaven, and loose on earth is loosed in heaven.” And gave Peter the keys to the kingdom. What people don’t understand about the Catholic sacrament of Reconciliation is this: During the Sacrament, you are being Reconciled by the Church Militant.
(Church Militant: the Living; Church Suffering: In Purgatory; Church Triumphant: In Heaven)
Meaning that you are forgiven for all members of the Church on Earth, as you should not harm the Body of Christ, and since that is what we are, each of our sins brings harm to the whole body, as when you stub your toe, your hand will reach for it. The rest of you looks out for the one part of you. The confession of sins to the priest, is mainly so that you lay it all out so that he can forgive you, representing the Church. He then can give you advice on how to overcome those sins that you have commited again and again, and hold you accountable. At the end, you make an Act of Contrition, which is when you pray to God for forgiveness, ask His mercy, and for the grace not to do it again, and to avoid the near-occasion of Sin. Reconciliation is a means to be right with the rest of the Church, which is an essential part of God forgiving you, as He said that if you have not forgiven your brother, you cannot be forgiven. Something like that.
Eucharist is the biggest one. When we disagree about that, we are in disagreement about Jesus, I think. John 6 is really huge, and being an odd number, John 6:66 was one of the most powerful parts of the chapter, that most people don’t understand, or don’t know what it means, or the gravity of it. It’s during the Last Supper, when Jesus says “Take this, all of you, and eat of it, for this is My Body, which has been given up for you.” What he said was something like “to nibble or to chew on My flesh,” which, at that time meant great insult to the person. So “He who does not eat of the Flesh and Drink of the Blood does not have life within them” basically would mean, if Jesus was speaking symbolically, that “He who does not insult Jesus, does not have life within them.” This is, of course, highly illogical and ridiculous. 1 Cor 11: 27-30 says: Therefore, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord. A man ought to examine himself before he eats of the bread and drinks of the cup. For anyone who eats and drinks without recognizing the body of the Lord eats and drinks judgment on himself. That is why many among you are weak and sick, and a number of you have fallen asleep.
Why would that be such a big deal, were it a mere symbol of Christ? It must be more real than that. It must also be Perpetuated: The Eucharist that Christ institutes at that moment will be the memorial of his sacrifice (1 Cor 11:25). Jesus includes the apostles in his own offering and bids them perpetuate it (Cf. Lk 22:19). By doing so, the Lord institutes his apostles as priests of the New Covenant: “For their sakes I sanctify myself, so that they also may be sanctified in truth” (Jn 17:19; cf. Council of Trent: DS 1752; 1764).
And that is why we have the Sacrifice of the Mass. It is not a “re-crucifixion, as some would have you believe, but a perpetuation, for God is outside of Time, and therefore, so too is the Crucifixion, which is why it is a mystery.