One thing I'm still a bit confused about is baptism.  First of all, baptism takes away original sin…but how exactly?  By the water being poured on us?  The words of the priest?
et's define a sacrament.  In the Baltimore Catechism it said:
A sacrament is an outward sign instituted by Christ to give grace.
While this is a reasonable definition, I think we can update it as follows:
A sacrament is a symbolic action derived by command or example from the ministry of Jesus by which we obtain a deeper sharing in the life of the Trinity.
Scott Hahn has shown that the sacraments are actually covenant oaths by which we bind ourselves to God who thereby pledges his benefits to us.  The symbol (i.e., pouring of water in baptism) is powerless in itself.  It is the promise of God that those who submit themselves to this symbolic action IN FAITH will receive a gracious benefit from Him.  In order to confect the sacrament properly, it must be done in the proper way to constitute a covenant ritual.  This means that there must be five things which conform to the five classes of causes:
1)
Appropriate matter for the ritual (e.g., running water, oil, wine, bread, a believing human subject.) [Material cause]
2)
Appropriate form (i.e., correct prayers and actions) [Formal Cause]
3)
Appropriate minister (e.g., layman, priest, deacon, bishop) [Efficient Cause]
4)
Appropriate intention (to do what the Church does in confecting a sacrament, NOT necessarily to do what the Church intends) [Final Cause]
5)
Appropriate continuity with the ministry of Jesus and Christian tradition [Exemplary Cause]
{By the way, the fifth cause is what is deficient in Anglican Orders according to Pope Leo XIII in the document Apostolicae Curae.  Even though they may sometimes meet the criteria in the other four categories, they still have not repudiated the 1549 Anglican ordinal and as such have a serious defect of intention that adheres to the entire Anglican tradition.}
With regard to baptism, anyone – even a pagan – can validly baptize someone. The only limit is that you cannot baptize yourself.  Infants are baptized because they are part of the faith community and have a natural faith in their parents good intentions for them.  As such, they do not present any impediment to the power of the sacrament.  While God has bound himself to the sacrament He is not limited by it.  He is also capable of bestowing His grace apart from the sacramental sign.  But the sign is His pledge to us that he will keep His promises.
And what does the Church believe happens at the moment of baptism…that the holy spirit descends upon the infant in an invisible way or something?
he same thing happems to us that happened to Jesus at his baptism in the Jordan River.  This story is told in the same form in all four gospels so it is VERY important.  All of the versions agree on these details: Jesus was:
1)
Baptized in real water
2)
For the forgiveness of sins
3)
The Holy Spirit descended on him
4)
God the Father publicly acknowledged him as his "beloved son"
[These details can be found in the Gospels at Matthew 3, Mark 1, Luke 3, and John 1.]
These four things parallel what St. Thomas Aquinas and the 6th Session of the Council of Trent taught about Justification:
1)
We turn towards God and away form sin
2)
Our sins are forgiven
3)
The Holy Spirit dwells within us (uncreated grace)
4)
We receive adoptive sonship in the image of Jesus (created grace)
I'm not exactly sure what the sacrament is all about.  And sometimes I think, "It must not be important if they say we can be baptized by blood and desire…"
ater baptism is the ordinary means of union with Christ.  Baptism of desire and baptism of blood are extraordinary means.  You are assured of the efficacy of the former one.  I would not depend on the latter two… they are concessions in hard cases and not the norm.  Besides in both cases, you have to DIE desiring baptism.
Plus I heard an "estoeric Christian" say that "all of the sacraments are, and have always been, representations of interior acts."  Now, I know this isn't true w/ regards to all the sacraments except Baptism…baptism puzzles me.
ach of the sacraments is an outward sign of an inward change.  But they are EFFICACIOUS signs that actually bring about what they signify.  While God can bestow His grace on anyone to whom it pleases Him to do so, He expects us to conform to His public revelation and not to tempt Him by asking for a special benefit.  The refusal to submit to the Catholic Church can be in itself grounds for damnation. (See Vatican II, Lumen Gentium, paragraph 14.)
Also, what is the difference between a valid baptism and an invalid one… and who is saying the valid one, and who today is saying the invalid one?
valid baptism is one that meets all five of the criteria mentioned above.  Many modern Protestant religions have deviated from proper matter (some use rose petals instead of water), proper form (some baptize in the name of Jesus, not in the name of the Father, Son, and Holy Spirit), proper minister (the person dunking the individual is not the person saying the words "I baptize you"), proper intention (some specifically intend NOT to baptize as the Catholic Church does) and proper continuity (the Mormons perform a ritual washing that they base on OT proselyte baptism).  Many of these egregious errors are occurring in mainstream Protestant religions so that many new converts (e.g., Scott Hahn) actually have themselves conditionally re-baptized.
St. Catherine of Siena says:
If you are against the Church, how can you participate in the blood of the Son of God?  For the Church is nothing other than Christ Himself.  Do you not know that the Catholic Church, of which He is the visible head, is a mystical body which has in itself the blood of Christ?  It is He who administers to us the Sacraments, which vivify us through the life which they receive from the blood of Christ; for, before this blood was given to us, neither virtue nor anything else was sufficient to give us lasting life.
Can you explain to me what she means by "participation in the blood of the son of God"?  What exactly is this blood which she claims is necessary for salvation?  And also what is meant by "the Church is nothing other than Christ Himself"?
he is paraphrasing St. Paul in the Vulgate Bible at 1 Corinthains 10:16 –
Calicem benedictionis cui benedicimus nonne communicatio sanguinis Christi est et panis quem frangimus nonne participatio corporis Domini est?
[Is not he cup of blessing that we bless a communication in the blood of Christ and the bread that we break a participation in the body of Christ?]
The blood of Christ was shed for our atonement and justification.  What she is saying is that one cannot benefit from the atonement of Christ apart form the Church.  Basically, she is reiterating that there is no salvation apart from the Catholic Church.  Everyone who is saved must be related to the Church in some way.  The Church is also – as St. Paul states in the above verse and elsewhere – the body of Christ himself.  By baptism we are united to him into one mystical body:
For as we have many members in one body, and all members have not the same office: So we, [being] many, are one body in Christ, and every one members one of another.  (Romans 12:4-5)
What?  Know ye not that he which is joined to an harlot is one body?  For two, saith he, shall be one flesh.  For we [being] many are one bread, [and] one body: for we are all partakers of that one bread.  (1 Corinthians 10:16-17)
For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also [is] Christ.  For by one Spirit are we all baptized into one body, whether [we be] Jews or Gentiles, whether [we be] bond or free; and have been all made to drink into one Spirit.  (1 Corinthians 12:12-13)
But now [are they] many members, yet but one body.  (1 Corinthians 12:20)
And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby…  (Ephesians 2:16)
[There is] one body, and one Spirit, even as ye are called in one hope of your calling;  (Ephesians 4:4)
And let the peace of God rule in your hearts, to the which also ye are called in one body; and be ye thankful.  (Colossians 3:15)
[Regarding "the Church is nothing other than Christ Himself."]
Well…yes and no.  God is the actual head of the Church and He is invisible.  Jesus is the mediator between God and man and is God himself so he is both an invisible (divine) and visible (human) head of the Church.  The Pope is actually the Vicar of Christ: the vicarious stand-in for Jesus.  When Jesus returns, he will head the Church himself.  I hope that helps.
Art Sippo
April 2, 2004