Did you read my reply to that question " way back":>)
1) None of us really know do we because scripture is silent on this right ?
2) We must there for assume that infants and children and the retarded are held to the same standard as adults
So what then can we know about the spiritual end of infants? We have to know that they , like us, are saved by Gods mercy and not their worth.
The minute you say they are free from sin and there for worthy to enter heaven 2 things happen
1) You have a salvation based on human works and not Gods grace or mercy
2) The birth of Jesus with out sin becomes meaningless . He was no more Holy at his birth then than we are.
Rom 3:10 As it is written, There is none righteous, no, not one:
There is no exception stated for age or intelligence
The bible asks "will not the judge of the world do right?"
Can we just let God be God and trust that no matter the answer He is doing what is just and right?
BTW Most Calvinists believe that God saves infants because of His mercy