All of these examples demonstrate that people are spiritually alive (as infants and young children) until sin "springs to life" within them, causing them to die spiritually. The Bible does not say at what age this happens (and possibly it happens at different ages for different people since everyone matures at a different rate), but the Bible does say that we need the new birth through Christ in order to receive spiritual life again. Now, here's something else to consider. Jesus said that we must become "like little children" in order to enter the kingdom of heaven: Matthew 18:3: "And he said: "I tell you the truth, unless you change and become like little children [paidion], you will never enter the kingdom of heaven." Matthew 18:4: "Therefore, whoever humbles himself [tapeinoo] like this child [paidion] is the greatest in the kingdom of heaven." Matthew 18:5: ""And whoever welcomes a little child [paidion] like this in my name welcomes me." Matthew 18:6: "But if anyone causes one of these little ones [mikros] who believe in me to sin, it would be better for him to have a large millstone hung around his neck and to be drowned in the depths of the sea." Matthew 19:14: "Jesus said, "Let the little children [paidion] come to me, and do not hinder them, for the kingdom of heaven belongs to such as these.""