Why did boy Jesus, 12 years old, remain behind in Jerusalem?

Question

Did boy Jesus left his parents intentionally to be about His Father's House/Business? If so, would that be correct to say that He might even have planned His visit to the Temple to stay in the midst of teachers even before making that trip to Jerusalem with His parents for the Passover? If so, might He have left them secretly in the fear of His parents not letting Him go by Himself to the Temple?

Or did His parents not pay attention and assumed He was traveling with them on their way back to Nazareth? If so, Jesus noticing He was left behind by His parents, decided at that point to visit the Temple?

I see two passages that could help finding an answer.

Luke 2:43 and as they were returning, after spending the full number of days, the boy Jesus stayed behind in Jerusalem. But His parents were unaware of it,

Luke 2:49 And He said to them, "Why is it that you were looking for Me? Did you not know that I had to be in My Father's house?"

1. Did Jesus go to the temple BECAUSE His parents forgot Him and therefore wanted to remain busy? OR
2. Did Jesus go to the temple BECAUSE that was His plan from the beginning?

To summarize: What triggered the separation between the parents and the child?

Thank you for your help.

Answer 1

In these passages, Jesus is going to Jerusalem for his Bar Mitzvah. By Jewish custom, he was now an adult (although still under his parents' authority). Some have surmised that He remained in Jerusalem to begin His ministry. But when His parents returned to Jerusalem and told Him to come home, because He was still under their authority, He was obedient and followed them. He did not begin His ministry until he turned 30 at which point, by Jewish custom, He was no longer under their authority and could disobey them without sinning.

He was not lost. He stayed behind deliberately, and his parents assumed He was in the company (the large group of Jews from Nazareth who journeyed to Jerusalem together for Passover each year).

Answer 2

This is my best guess given what are written in the Bible and what are consistent with Jesus, Mary, and Joseph's characters.

Luke 2:41 Every year Jesus’ parents went to Jerusalem for the Festival of the Passover.

This was an annual event with set habits and customs.

43 After the festival was over, while his parents were returning home, the boy Jesus stayed behind in Jerusalem, but they were unaware of it. 44 Thinking he was in their company, they traveled on for a day. Then they began looking for him among their relatives and friends.

In previous years, when the festival was over, Jesus' parents had no need to make sure that He had departed Jerusalem with them at the same time. They just assumed that He was either with their relatives or friends traveling in the same direction. They had complete confidence in the boy Jesus.

However, this year was different. Jesus didn't depart with any of them.

The question is: Why not?

Meanwhile, Jesus was engaging the Jewish teachers, totally absorbed in the discussions of the Scripture. They were surprised at His young intellect. Jesus felt at home in the temple.

46 After three days they found him in the temple courts, sitting among the teachers, listening to them and asking them questions. 47Everyone who heard him was amazed at his understanding and his answers.

Now, back to trustful parents, after a day, Jesus still hadn't checked in with them. They started to worry and looked for Him. He was not with group! Now they started to panic and headed back to Jerusalem.

Well, you know the rest of this story. Now I am going to answer OP's good questions directly.

Did Jesus go to the temple BECAUSE His parents forgot Him and therefore wanted to remain busy?

No, His parents didn't forgot Him. They took for granted that He was with relatives and friends.

No, Jesus stayed at the temple because he felt at home there. He felt purposeful there with the Jewish teachers.

49 “Why were you searching for me?” he asked. “Didn’t you know I had to be in my Father’s house?”

Did Jesus go to the temple BECAUSE that was His plan from the beginning?

No, it was spontaneous. He would not premeditate an act that could worry His parents.

What triggered the separation between the parents and the child?

They trusted him. They had complete confidence in Him. He had always been obedient. The temporary separation was no big deal in previous years.

51 Then he went down to Nazareth with them and was obedient to them.

Why did boy Jesus, 12 years old, remain behind in Jerusalem?

To mind His Father's business. It was the will of the Father.

John 2:17 His disciples remembered that it is written: "Zeal for your house will consume me."

Answer 3

D. Brent has given a good answer.

To address the concerns of the OP that references to "Bar Mitzvah" are not found the Bible, there are other early texts that provide the necessary support for it.

He used to say: At five years of age the study of Scripture; At ten the study of Mishnah; At thirteen subject to the commandments; At fifteen the study of Talmud; At eighteen the bridal canopy; At twenty for pursuit [of livelihood]; At thirty the peak of strength; At forty wisdom; At fifty able to give counsel; At sixty old age; At seventy fullness of years; At eighty the age of “strength”; At ninety a bent body; At one hundred, as good as dead and gone completely out of the world.
_{Pirkei Avot 5:21}

This interesting saying is attributed to Judah ben Tema who, according to the Encyclopedia of Judaism was one of the Tannaim i.e. "rabbinic sages whose views are recorded in the Mishnah, from approximately 10-220 CE.

So, Jesus would have been encouraged by his community to study the Scripture from age 5 as he approached the age of subjection to the commandments at age 13. Jesus was at the peak of his strength when he began publicly teaching at age 30.

It is easy to see from this reference one of the significant reasons why Jesus irked the Jewish religious leaders since in their eyes he had not yet attained the age of wisdom, which they considered to be 40.

Answer 4

The reason Jesus stayed behind is:

1. Plan - before he and the family left for Jerusalem he had planned to stay behind to start his journey of public ministry. I feel that his ministry started when he was born of a virgin and conceived by the Holy Ghost. He didn't have a large group but the ministry started with God entrusting Mary and Joseph to follow through with the plan of birthing and raising Jesus in a holy household full of God's Spirit!
2. Purpose - Jesus knew His purpose before conception. He is the incarnate Word of God. His main objective was to be obedient to his Heavenly Father-God and to live in human form, die for the sins of the world. And, to be raised with VICTORY over death, hell, and grave (and the devil and imps). Passion - His passion was simply to do the will of God the Father!