So the children and babies do not have to repent and they get the Holy Spirit? They get born again without repenting?
Now you are getting it!

What post number are we on?
If that were the case, then 2000 years ago, the first person who repented would have covered every generation after him till today. His children would be born again without repenting then the children’s children would be born again without repenting and so on and so on.
Well, yes an no. What you are saying is true, that this practice has been going on for 2000 years until today. However, not everyone baptized holds onto their faith (you make a good example of that

) And not everyone is able to go through their whole life without sin, so repentance is still needed.
Yes, repentance is the key to continue walking in a state of grace. In baptism, sins are washed way, both original, and personal. After that, repentance washes away personal sin.
Why do you think the Apostles Creed says “one baptism for the forgiveness of sin”? Did you think that was made up recently?
Each person must do it to be born again.
Yes, persons who are able to repent are required to do so. The very young, very old, and incapacited are not.
One person cannot do it for another.
Maybe that is the subject for another thread?
James 5:19-20
19 My brethren, if any one among you wanders from the truth and some one brings him back, 20 let him know that whoever brings back a sinner from the error of his way **will save his soul **from death and will cover a multitude of sins.
Jude 22-23
2 And convince some, who doubt; 23
save some, by snatching them out of the fire; on some have mercy with fear, hating even the garment spotted by the flesh.
Rom 11:13-15
I magnify my ministry 14 in order to make my fellow Jews jealous, and thus
save some of them.