How old were Jesus’ disciples?
Here's the answer:
The Bible doesn't tell us exactly how old Jesus' disciples were.
Despite the Bible not telling us directly how old Jesus’ disciples were, there are many things we can know. Jesus was around 30 years old when He started His ministry. According to Jewish culture and tradition, a student was generally younger than their teacher. Since Jesus was 30 years old when he started his ministry, we can assume that the disciples were all younger than He was.
James and John were fishermen, which meant they were old enough to have jobs. This means they were not little children. They had to be either teens or adults, but probably not over the age of 30. Peter is said to have a wife, which would mean he had to be old enough to have a wife. In Jewish custom, this meant he had to at least be a teenager.
It was common during Jesus' day for boys to start training in Jewish Law at the age of 5. By 12 or 13 years old, they could be trained under a teacher. If they chose to continue in their study, they would train under their teacher until they were 30 years old. This would mean that the disciples were anywhere from 13-30 years old when they started following Jesus.
"Jesus was about 30 years old when he began his special work for God and others. It was thought that he was the son of Joseph…" (Luke 3:23).
"Going on from there, he saw two other brothers. They were James, son of Zebedee, and his brother John. They were in a boat with their father Zebedee. As they were preparing their nets, Jesus called out to them. Right away they left the boat and their father and followed Jesus" (Matthew 4:21-22).
"When Jesus came into Peter’s house, he saw Peter’s mother-in-law. She was lying in bed. She had a fever" (Matthew 8:14).