Nobody can say that I avoid tough topics.
So, what happens to such children? This question is one that many Christian parents must face at some point.
We know that everyone is conceived and born already guilty before God (Psalm 51:5). Therefore, even the unborn must be saved through the forgiveness of sins that is only found in Jesus Christ (Acts 4:12). In the case of infants, God alone can detect whether they have faith in Jesus, because we humans rely upon the the outward confession of faith. We can’t see into someone’s heart, even the heart of an infant. How can we be sure that any infant is saved? We know that faith is required, and works do not avail (Romans 11:6, Ephesians 2:8-9). Since works are excluded, but faith is required, it follows naturally that faith is not a work. It is a gift from God.
How does God provide this gift of faith? Through God’s Word of forgiveness (Romans 1:16) and through Baptism, which is a special application of that Word (Mark 16:15-16, Acts 2:38-39). It may seem that the Word must be cognitively understood in order to be effective. That seems reasonable, but it’s not necessarily true. In fact, it’s quite likely that the Word has power to create faith in infants who do not yet speak (Luke 18:15-17, Isaiah 55:11). Furthermore, there is no reason to suppose that God cannot grant the gift of faith through Baptism to little infants. So we can be sure that infants who have been baptized into Christ and who hear the Gospel are saved through faith in Christ.
What about the unborn? We should note that the unborn can detect sounds from outside the womb, and it is possible that they attach some significance to what they hear (Luke 1:44). This would be especially true in the case of God’s Word, since it has an efficacy of its own from the Holy Spirit. Furthermore, there is a parallel between Old Testament circumcision (the sign of God’s covenant with Abraham and his descendants) and New Testament baptism (the seal of God’s gracious adoption in Jesus Christ) — see Colossians 2:11-12. Only the baby boys underwent circumcision, not the baby girls. Yet the Hebrew women and girls were also included in the covenant of which circumcision was a sign. They were included not by the act of circumcision itself, but through their connection to the family where the covenant is believed. The outward sign of that faith (and the promise too) was the circumcision of the boys (Romans 4:9-12).
Today, in the time of the New Testament, we have been given the sacrament of baptism, which provides rebirth, forgiveness of sins, and the righteousness of Jesus Christ by connecting the baptized sinner to Him (Matthew 3:15, Mark 1:4, Acts 22:16, Romans 6:3, Galatians 3:27, Titus 3:5-7). When a baby is born who may not survive very long, Christians will baptize the baby immediately, to be sure that God’s precious gift has been provided. When a baby dies in the womb, that is not possible. What are Christian parents to think of this?
We are to remember that God is gracious and merciful. His promise to you is certain, sealed by the blood of Jesus Christ. Our times are in His hands, and it was His wisdom that allowed the unborn child to die in the womb. He knows that you planned to baptize the child and bring him to receive the precious Gospel on a regular basis. You probably brought the child to hear the Word already, even while he was living. It is certain that our loving God has provided what was necessary for His little one to be saved.
This comfort can not be given to parents who treat salvation and God’s Word so lightly that they did not plan to baptize their child, and intentionally stayed away from the preaching of the Gospel. Such a family would be like the unbelieving Philistines of the Old Testament: outside the covenant that God made with Abraham. But a family of faith, that esteems the Word of God and His gift of baptism highly, can be sure that God’s mercy in Christ Jesus can not fail.