Many Christians understand there to be an age of accountability.  This belief holds that children under a certain age who die are not held accountable for their sins as they are unable to understand right from wrong and unable to understand Jesus' death on the cross.  This is typically not considered a form of inclusivism however.

Also included in the age of accountability are those who are mentally handicapped and would have the mental capacity of a child.

There appears to be little Biblical evidence for an age accountability outside of David's comments in 2 Samuel 12:21-23.  After the death of his son born out of adultery to Bathsheba he says, "I will go to him, but he will not return to me." David appears to understand that he will be with his infant son once again.

Other arguments for an age of accountability are based on God's nature.  Most Christians cannot fathom a loving and merciful God sending a child to hell.

There is no standard age that one becomes accountable.  Some hold to thirteen as the age of accountability however because this is when a Jewish boy became a man.

Baptism plays a part in an age of accountability according to some as well.  Infants who are baptized are not held accountable until they reach accountability whereas those with unbelieving parents or who otherwise simply are not baptized as an infant are held accountable for their sins from birth.  This is viewpoint is derived from the belief that baptism replaced circumcision in God's commands as God's blessings were passed from Israel unto the church.