As such, it's not quite as "unscriptural" as I first deemed it.
Deuteronomy 6 makes it clear that parents are to teach their children in the ways of God. Whereas the primary responsibility for teaching the children was given to the parents, the synagogue developed as a more community-oriented method of teaching the children. So a case could be made that the scriptures say "teach your children" and not "build schools to teach your children", but Yahshua himself appears to have been comfortable with the notion of a community synagogue, taking advantage often of teaching in them everywhere he went.
So, to reiterate: my former understanding that the synagogue was a "replacement" for Temple worship was an incorrect understanding; rather, the synagogue was primarily a place of religious learning, not of worship. Accordingly, this does not really serve as an example of an unscriptural, man-made worship format which was later accepted by God, as I had earlier deemed it.
The synagogue appears to have become more of a place of worship after the destruction of Jerusalem (and the second Temple) in A.D. 70, but during Yahshua's ministry, it was a school of religion, not a church. This can be seen by a simple perusal of the hits returned by a search for the word "synagogue" at Biblegateway.com, using the Holman Christian Standard Bible version. Below are some examples from that search; note that it's primarily a place of teaching, discussion, disputing, and reasoning (although prayer, healing, and perhaps worship also take place in it):
- Matthew 4:23
[ Teaching, Preaching, and Healing ] Jesus was going all over Galilee, teaching in their synagogues, preaching the good news of the kingdom, and healing every disease and sickness among the people.
Matthew 4:22-24 (in Context) Matthew 4 (Whole Chapter)
- Matthew 13:54
[ Rejection at Nazareth ] He went to His hometown and began to teach them in their synagogue, so that they were astonished and said, "How did this wisdom and these miracles come to Him?
Matthew 13:53-55 (in Context) Matthew 13 (Whole Chapter)
- Mark 1:21
[ Driving Out an Unclean Spirit ] Then they went into Capernaum, and right away He entered the synagogue on the Sabbath and began to teach.
Mark 1:20-22 (in Context) Mark 1 (Whole Chapter)
- Mark 6:2
When the Sabbath came, He began to teach in the synagogue, and many who heard Him were astonished. "Where did this man get these things?" they said. "What is this wisdom given to Him, and how are these miracles performed by His hands?
Mark 6:1-3 (in Context) Mark 6 (Whole Chapter)
- Luke 4:15
He was teaching in their synagogues, being acclaimed by everyone.
Luke 4:14-16 (in Context) Luke 4 (Whole Chapter)
- Luke 4:16
[ Rejection at Nazareth ] He came to Nazareth, where He had been brought up. As usual, He entered the synagogue on the Sabbath day and stood up to read.
Luke 4:15-17 (in Context) Luke 4 (Whole Chapter)
- Luke 6:6
[ The Man with the Paralyzed Hand ] On another Sabbath He entered the synagogue and was teaching. A man was there whose right hand was paralyzed.
Luke 6:5-7 (in Context) Luke 6 (Whole Chapter)
- Luke 13:10
[ Healing a Daughter of Abraham ] As He was teaching in one of the synagogues on the Sabbath,
Luke 13:9-11 (in Context) Luke 13 (Whole Chapter)
- John 6:59
He said these things while teaching in the synagogue in Capernaum.
John 6:58-60 (in Context) John 6 (Whole Chapter)
- John 18:20
"I have spoken openly to the world," Jesus answered him. "I have always taught in the synagogue and in the temple complex, where all the Jews congregate, and I haven't spoken anything in secret.
John 18:19-21 (in Context) John 18 (Whole Chapter)
- Acts 13:5
Arriving in Salamis, they proclaimed God's message in the Jewish synagogues. They also had John as their assistant.
Acts 13:4-6 (in Context) Acts 13 (Whole Chapter)
- Acts 13:15
After the reading of the Law and the Prophets, the leaders of the synagogue sent [word] to them, saying, "Brothers, if you have any message of encouragement for the people, you can speak."
Acts 13:14-16 (in Context) Acts 13 (Whole Chapter)
- Acts 17:17
So he reasoned in the synagogue with the Jews and with those who worshiped God, and in the marketplace every day with those who happened to be there.
Acts 17:16-18 (in Context) Acts 17 (Whole Chapter)
- Acts 18:4
He reasoned in the synagogue every Sabbath and tried to persuade both Jews and Greeks.
Acts 18:3-5 (in Context) Acts 18 (Whole Chapter)
- Acts 18:19
When they reached Ephesus he left them there, but he himself entered the synagogue and engaged in discussion with the Jews.
Acts 18:18-20 (in Context) Acts 18 (Whole Chapter)
- Acts 18:26
He began to speak boldly in the synagogue. After Priscilla and Aquila heard him, they took him home and explained the way of God to him more accurately.
Acts 18:25-27 (in Context) Acts 18 (Whole Chapter)
- Acts 19:8
[ In the Lecture Hall of Tyrannus ] Then he entered the synagogue and spoke boldly over a period of three months, engaging in discussion and trying to persuade them about the things related to the kingdom of God.
Acts 19:7-9 (in Context) Acts 19 (Whole Chapter)
- Acts 24:12
And they didn't find me disputing with anyone or causing a disturbance among the crowd, either in the temple complex or in the synagogues, or anywhere in the city.
Acts 24:11-13 (in Context) Acts 24 (Whole Chapter)