I've always wondered this. Before they even have a chance to think for themselves, and they die in sin, does God send them to Hell?
If we can determine what sin is, we can determine if God would be able to punish a child for it. Fortunately Jesus will never leave us in the dark. He gives us a definition of what sin is in the book of 1 John 3:4 which states “Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.” 1 Sin is the transgression or the breaking of God’s law, His Ten Commandments. Because of this we must ask which of the Ten Commandments has a child violated? Has an infant murder, lying, theft, adultery, Sabbath-breaking or blasphemy? Certainly not. Is crying a sin? “Jesus wept”. (John 11:35) Jesus gives us great insight into how God judges sin when He said…
“If you were blind, you would have no sin; but now you say, ‘We see.’ Therefore your sin remains.” (John 9:41)
Listen closely, children are born with a sinful nature that is we have this inward pull or desire to sin but we are not born sinners. Sin is the breaking of God’s law. And we have concluded that babies have not broken the Ten Commandments. Even if they did, Jesus told us in John 9:41 that were there is no understanding, there is no sin. Again Jesus said
“If I had not come and spoken to them, they would have no sin, but now they have no excuse for their sin.” (John 15:22)
Where there can be no knowledge, there can be no sin.
Imagine if one day a group of police officers showed up at your door. They quickly handcuffed you, you were taken to a courtroom and declared guilty of war crimes. “War crimes, I’ve never fought in a war!” you plead. The judge responds and says “your great grandfather committed war crimes in World War 1 and we are punishing you for the crime, I hereby sentence you to death”.
Certainly a human judge would never make such an unfair sentence. How could you be judged for a crime that occurred when you never even were alive? Yet would God throw someone in hell because of the sins of their parents, or grandparents? Or because of the sins of Adam in the garden of Eden? Does the guilt of one generation pass on from generation to generation through a bloodline? The Bible gives us the answer in Ezekiel 18:20 when it says
“The soul who sins shall die. The son shall not bear the guilt of the father, nor the father bear the guilt of the son. The righteousness of the righteous shall be upon himself, and the wickedness of the wicked shall be upon himself.“
Here the Bible says the son shall not bear the guilt of the father. Again the Bible says “Fathers shall not be put to death for their children, nor shall children be put to death for their fathers; a person shall be put to death for his own sin.” (Deuteronomy 24:16) You are not punished for the sins of any past generation. “God is a just judge” (Psalm 7:11) and God is much fairer than any human court. It is true, sin does have consequences. If your parents were abusive you may have suffered the consequences, when Adam sinned the earth received the curse of death, but the guilt of one generation does not pass from generation to generation. This would be unfair. Only those who have sinned will be condemned.
The book of Isaiah chapter 65 tells us that yes, infants will be in heaven for it is written
“For behold, I create new heavens and a new earth; And the former shall not be remembered or come to mind. I will rejoice in Jerusalem, and joy in My people; The voice of weeping shall no longer be heard in her, nor the voice of crying. No more shall an infant from there live but a few days”. Isaiah 65:17,19-20
When Exodus 20 talks about visiting the iniquities to the third and fourth generation, it means sinful tendencies are transferred from generation to generation (example, Abraham, Isaac and Jacob all struggled with lying, David and Solomon struggled with women, etc). It does not mean people are thrown in hell for the sins of their grandfathers.
The Catholic Church professes that unbaptized infants go to a part of Hell where there is no fire, known as The Limbo of the Children
Pope Gregory X, Council of Lyons II, 1274: “The souls of those who die in mortal sin or with original sin only, however, immediately descend to Hell, but to be punished with different punishments. (Denz. 464)
Pope Eugene IV, Council of Florence, “Letentur coeli,” Sess. 6, July 6, 1439, ex cathedra: “We define also that… the souls of those who depart this life in actual mortal sin, or in original sin alone, go straightaway to hell, but to undergo punishments of different kinds.” (Denz. 693)
St. Augustine, A.D. 415: “Anyone who would say that infants who pass from this life without participation in the Sacrament [of Baptism] shall be made alive in Christ truly goes counter to the preaching of the Apostle and condemns the whole Church, where there is great haste in baptizing infants because it is believed without doubt that there is no other way at all in which they can be made alive in Christ.” (Jurgens, The Faith of the Early Fathers, Vol. 3: 2016.)
However the current hierarchy claims that there is no such thing as limbo and it in fact was never defined, "[There are] reasons to hope that there is salvation for these babies", quoting the Rev. Luis Ladaria, a Jesuit who is the commission's secretary-general to The Associated Press.