What do you think Jesus and the disciples did in the synagogues? What do you call worship?
The NT was written many years after the resurrection oil Jesus, yet the 7th day is still called the sabbath. The disciples were still teaching on the sabbath in the synagogues---and it wasn't to reach the gentiles, they wouldn't haver been allowed into them. The disciples met on the 1st day of the week a couple times---it was not to worship.
Luk_4:16 And he came to Nazareth, where he had been brought up: and, as his custom was, he went into the synagogue on the sabbath day, and stood up for to read.
Luk_4:31 And came down to Capernaum, a city of Galilee, and taught them on the sabbath days.
Luk_6:6 And it came to pass also on another sabbath, that he entered into the synagogue and taught: and there was a man whose right hand was withered.
Luk_13:10 And he was teaching in one of the synagogues on the sabbath.
Luk_14:1 And it came to pass, as he went into the house of one of the chief Pharisees to eat bread on the sabbath day, that they watched him.
Act_13:14 But when they departed from Perga, they came to Antioch in Pisidia, and went into the synagogue on the sabbath day, and sat down.
Act_13:27 For they that dwell at Jerusalem, and their rulers, because they knew him not, nor yet the voices of the prophets which are read every sabbath day, they have fulfilled them in condemning him.
Act_13:42 And when the Jews were gone out of the synagogue, the Gentiles besought that these words might be preached to them the next sabbath.
Act_13:44 And the next sabbath day came almost the whole city together to hear the word of God.
Act_15:21 For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day.
Act_16:13 And on the sabbath we went out of the city by a river side, where prayer was wont to be made; and we sat down, and spake unto the women which resorted thither.
Act_17:2 And Paul, as his manner was, went in unto them, and three sabbath days reasoned with them out of the scriptures,
Act_18:4 And he reasoned in the synagogue every sabbath, and persuaded the Jews and the Greeks.
For more on the subject--85 times the disciples met on sabbath in the book of Acts alone:
The Disciples Kept the Sabbath 85 Times in Acts