I don't believe that original sin is scriptural at all. In fact Ezekiel 18 teaches the exact opposite. Verse 20 gets right to the point, but if you read the entire section starting at verse 1 its more insightful;
Exekiel 18:20
The person who sins will die. The son will not bear the punishment for the father's iniquity, nor will the father bear the punishment for the son's iniquity; the righteousness of the righteous will be upon himself, and the wickedness of the wicked will be upon himself.
How can a child be born with sin if the iniquity of those who have lived before it are not counted against it? It can't. There is also another important distinction that needs to be made: living with the consequences of sin are different than bearing the punishment for that sin. I might sin and cause someone to die (murder). They have suffered the consequences of my sin but have not suffered the punishment for that sin.
-it sounds like you may be misunderstanding what original sin is. It is not a personal sin, but an inhereted one. And it is not a sin at all, but it is the result of the very first, original sin of Adam. It is the lack of sanctifying grace. One of the results of Adam's sins was the closing of heaven to the human race. So no human, no matter how good, or even ones who had been given sanctifying grace, could enter heaven until Christ came to open the gates again. That is part of original sin as well. That is why the OT saints did not go up to heaven, but down to sheol when they died, to the realm of the dead.
Consider:
Paul spells out the problem:
Romans 5:12-19
Therefore as sin came into the world through one man and death through sin, and so death spread to all men because all men sinned.
Yet death reigned from Adam to Moses, even over those whose sins were not like the transgresion of Adam, who was a type of the one who was to come..
And then Romans 6:
3 Or are you unaware that we who were baptised into Christ Jesus were baptised into his death?
Christ tells us that we are to come to Him as little children - this wouldn't make sense if there was something inherently wrong with the children.
Psalm 51:5:
"True, I was born guilty,
a sinner, even as my mother conceived me."
-however, that sounds harsh without proper perspective.
Matt 18:2-5
And calling to him a child, he put him in the midst of them and said, "Truly, I say to you, unless you turn and become like children, you will never enter the kingdom of heaven. Whoever humbles himself like this child, he is the greatest in the kingdom of heaven. Whoever rececives on such child in my name receives me." (In my name: Acts 2:38: repent and be baptised, every one of you, in the name of Jesus Christ; Acts 10:48 "He ordered them to be baptised int he name of Jesus Christ; Acts 19:5 "When they heard this, they were baptised in the name of the Lord Jesus.)
"Notice that we must come to Jesus in the New Covenant, as children. It would be strange to say that we must come to him as children, but then exclude the very children he claims we must be like, from entering communion with him through baptism!"
thing to think about is that this idea of original sin has its roots in gnostic teachings. They believed that sin was transferred through the flesh, which is the same idea that you're purveying. If this is carried through to the logical conclusion then Christ was born with sin. He was afterall flesh.
-nope that is absolutely false. You misunderstand what original sin is. It is not transferred in the flesh, it is the lacking of something in the soul, sanctifying grace. Adam and Eve had it, and their obedience was the "condition" on whether their descendents would be born with or without it. They disobeyed and yet Christ was obedient unto death. Through him we are restored and we receive the sanctifying grace that Adam and Eve were created with and lost.
Christ and Mary are the New Adam and the New Eve. Just as Adam and Eve who caused the fall were created without Original Sin, so we say of Christ and Mary were conceived without original sin, Christ because he was God and like us in all things but sin, and Mary because she was given this grace for the purpose of Christ and his work. She too was obedient as Eve was disobedient. (but that's another subject as well).
Genesis 3:15
"I will put enmity between you [serpent]and the woman [Mary],
and between your offspring [sin] and hers [Jesus];
He will strike at your head, [crush skull, Jesus conquered evil by his crucifixion, in the Place of the Skull}, while you strike at his heel. [Christ's archilles heel of flesh].
The gnostics, unlike catholics, did carry this out to the logical end and therefore had to conclude that Christ did not come in the flesh, which is false. If the idea of original sin is true, then Christ was born with sin also. Doesn't fly.
-only if you misunderstand the teaching.
If this idea of original sin is incorrect, which I believe it is, then the entire view of baptism that you've laid out so far cannot be correct.
-Catholics, Orthodox and most Protestants accept the teaching of original sin, so you can't point the finger at us. The Catholic Church is the one who decided the Cannon of the NT having rejected outright any book with Gnostic influence.
I'm also not sure if you completely understand the nature of the Old Covenant. The Jews were members of that covenant because of whom they were born to. They were born into the covenant and then educated about it. Under the New Covenant, things are different. We are taught about God, and then enter into the New Covenant. You have to believe before you can be baptized.
-You fail to take in certain considerations.
Christ says that one must be born again to enter the Kingdom of Heaven. You will tell me that to be born again means to believe and accept Christ as your personal Lord and Savior after the age of reason. So you say then babies cannot believe. So you then in fact, consign infants to hell.
Christ says be born again, you say that is faith, babies cannot have faith, can't be born again.
We however, say that to be born again meand to be born of water and spirit, baptism, and even babies can be born again for they did not have sanctifying grace at birth.
As for the Old Testament, consider this:
Genesis 17
9 God said further to Abraham, "Now as for you, you shall keep My covenant, you and your descendants after you throughout their generations.
10 " This is My covenant, which you shall keep, between Me and you and your descendants after you: every male among you shall be circumcised.
11 "And you shall be circumcised in the flesh of your foreskin, and it shall be the sign of the covenant between Me and you.
12 "And every male among you who is eight days old shall be circumcised throughout your generations, a servant who is born in the house or who is bought with money from any foreigner, who is not of your descendants.
13 "A servant who is born in your house or who is bought with your money shall surely be circumcised; thus shall My covenant be in your flesh for an everlasting covenant.
14
"But an uncircumcised male who is not circumcised in the flesh of his foreskin, that person shall be cut off from his people; he has broken My covenant."
and Moses was rebuked for not circumcizing his son:
"On the journey, at a place where they spent the night,
the Lord came upon Moses and would have killed him. but Zipporah
took a piece of flint and cut off her son's foreskin....Then God let Moses go. At that time she said, "A spouse of my blood," in regard to the circumcision." Ex 4:24-26
And Joshua:
Joshua 5
2 At that time the LORD said to Joshua, "Make for yourself flint knives and circumcise again the sons of Israel the second time."
3 So Joshua made himself flint knives and circumcised the sons of Israel at Gibeath-haaraloth.
4 This is the reason why Joshua circumcised them: all the people who came out of Egypt who were males, all the men of war, died in the wilderness along the way after they came out of Egypt.
5 For all the people who came out were circumcised, but all the people who were born in the wilderness along the way as they came out of Egypt had not been circumcised.
6 For the sons of Israel walked forty years in the wilderness, until all the nation, that is, the men of war who came out of Egypt, perished because they did not listen to the voice of the LORD, to whom the LORD had sworn that He would not let them see the land which the LORD had sworn to their fathers to give us, a land flowing with milk and honey.
7 Their children whom He raised up in their place, Joshua circumcised; for they were uncircumcised, because they had not circumcised them along the way.
About Iraneaus: I appreciate the fact that you are trying to offer supporting evidence, but I'm not going to take the word of a man over what the Bible teaches. There were plenty of false doctrines and precepts floating around - too many in fact - to trust anything that a man has written. The Bible doesn't teach infant baptism, so I don't believe it. It's nothing personal, I assure you , I just don't think it matters what uninspired men say.
-Iranaus and many others can prove that infant baptism was done by the Early Christians/Church without question. It is used to prove the apostolicity of the teaching and of course there is many more. Your belief is one that the Apostles did not teach.
The Bible neither explicitly proclaims infant baptism, nor does in explicity deny it, however, there is more evidence for it then against it, and looking back to historical evidence of the historic Church, the evidence then becomes overwhelming. Besides the fact that nobody denied it until the Reformation while even the Reformers practiced infant baptism.
And you have to acknowledge that many of the false teachings floating around were by those that denied the Trinity, the Incarnation and many other things. It is the Catholic Church who defined the Trinity for you (for it is not explicit in the Bible), the incarnation, and the cannon of the NT which they compiled, and declared infallible, while also preserving it for you for over 1500 years. All I'm saying is that there is more to the story than your interpretation.
"Who is so impious as to wish to exclude infants from the kingdom of heaved by forbidding them to be baptised and born again in Christ?
This the Church always held; this she received from the faith of our ancestos; this she perseveringly guards even to the end."
St. Augustine
So then, am I not saved and going to hell due to this? 
