The Bible does not give an age requirement for when children can be baptized and then participate in Communion. Children should participate in these ordinances only when they understand Jesus and freely choose to follow Him.
The Bible provides no specific age requirement for when children can be baptized or participate in Communion. God has always called His people to teach children His ways, which will lead them to personally following Him (Deuteronomy 6:6-7; Proverbs 22:6). Baptism is a New Testament ordinance that follows salvation (Mark 16:16; Acts 2:38, 8:36-38), which comes when a person-child or adult—recognizes their own sin, their need for a Savior, and personally puts their trust in Jesus’ death and resurrection for the forgiveness of sins.
Communion, also a New Testament ordinance, is reserved for baptized believers who understand Christ’s sacrifice (1 Corinthians 11:23-29). Since infant baptism is not explicitly found in Scripture, children should be baptized only when they comprehend salvation and freely choose to follow Jesus, with guidance from parents and church leaders affirming their faith. Likewise, children should partake in Communion only after understanding its meaning and after baptism, ensuring that participation in both ordinances reflects conscious faith and personal commitment to Christ.
The practice of infant baptism did not take place in the New Testament but was later developed in the church to "christen" or commit a child to the Lord. While it may not be specifically wrong to baptize an infant, this is an extra-biblical tradition. Those who come to faith in Christ are still encouraged to receive believer's baptism. The biblical pattern of baptism was one of immersion in water.
How young should a child be baptized? Since no child baptisms were clearly shown in the Bible, the only guideline is that it takes place after salvation. Some children may understand the gospel message enough to express salvation at the age of five or six while others will be teenagers before understanding well enough to decide to follow Jesus.
Some churches make guidelines to not baptize children until the age of twelve or thirteen to refrain from baptizing children too young to understand the decision they are making. Other churches instead require a children's baptism class to help children understand their decision to follow Jesus and the importance of baptism. Parents should be involved in their child's baptism decision as much as possible. Baptism of a child would not typically be conducted without the consent of a parent, since the parent is responsible for the spiritual upbringing of a child.
Rather than at a specific age, baptism should take place when a person understands salvation and is choosing baptism to identify as a believer in Jesus. Parents and church leadership should be involved in the decision to ensure the child's understanding. Similarly, people should only take Communion when they understand salvation and the significance of Communion. Once again, parental guidance and church leadership can be useful for introducing children to Communion. And as with adults, children who take Communion should examine themselves and take it in a worthy manner (1 Corinthians 11:28).