Well, here's a good one to start with;
John 3:3 says 'Unless a man be born again he can not enter the kingdom of God'.
When Jesus was asked to explain how someone is born again, he answered;
John 3:5 'Unless a man be born again of water and the Holy Spirit he can not enter the kingdom of God'.
Just from this one scripture is is already clear that being 'born again' and being 'baptized' are the same thing.
There are a number of interpretations of John 3:5 that I've heard before in reference to being born of water. Being born of water is said to mean:
1. the first, natural birth
2. being washed with the word of God
3. being washed (or born of) by the Holy Spirit
4. baptism
Given that there are many legitimate intrepretations why do you feel that number 4 is the proper understanding. Also, what version of the Bible do you use? Because you quoted John 3:5 as saying
"Unless a man be born
again of water and the Holy Spirit he can not enter the kingdom of God'." (my bold).
After a quick search of 10 or 12 different versions of the Bible I was unable to find any that included the word "again". They all read as versions of "Unless a man be born of water and the Holy Spirit he can not enter the kingdom of God". That's a significant difference with the 'again' the implication seems to be natural birth - whereas, with the 'again' included the interpretation of natural birth would be precluded.
Nope. It is faith that got you into the water in the first place! Otherwise, you just went for a swim In the case of infants, it is the faith of the parents drawing down God's grace for them. If you don't think that is possible, think about this scripture;
Matthew 8:8; 'Lord I am not worthy that you should come under my roof, but only say the word and my servant shall be healed'.
And Jesus was astonished at the faith of the centurion, and said to him:
'Go thy way, as you have believed, so shall it be done to thee.'
Sure, it's a great example of Jesus' compassion but it's dangerous to treat such an example as this as being normative - especially in the face of clear doctrinal teaching that nowhere allows for one person's faith to gain salvation for another...