Now when they had passed through Amphipolis and Apollonia, they came to Thessalonica, where there was a synagogue of the Jews. And Paul went in, as was his custom, and on three Sabbath days he reasoned with them from the Scriptures, explaining and proving that it was necessary for the Christ to suffer and to rise from the dead, and saying, “This Jesus, whom I proclaim to you, is the Christ.”
(Acts 17:1-3 ESV)
Paul was trying to convince fellow Jews – Jesus was indeed the Christ / Messiah.
This is the primary doctrine they preached to the Jews in Acts as already seen in the following posts:
100 Reasons why the Bible does not use the word Trinity: Reason 4 of 100 [Witness to Cornelius – Jesus is Messiah or Anointed – God anointed Jesus of Nazareth with the Holy Spirit / God raised him on the third day / Jesus is the one appointed by God to be judge]
100 Reasons why the Bible does not use the word Trinity: Reason 6 of 100 [Paul’s speech at Antioch to the Jews – No hint of any form of trinity – ‘You are my Son, today I have begotten you / I will give you the holy and sure blessings of David / Through this man forgiveness of sins is proclaimed to you / YHWH raised him from the dead]
The general expectation by the Jews from the messiah was the restoration of Israel.
There are many prophecies that the Messiah would be a world ruler. Example:
It shall come to pass in the latter days that the mountain of the house of the LORD shall be established as the highest of the mountains, and shall be lifted up above the hills; and all the nations shall flow to it, and many peoples shall come, and say: “Come, let us go up to the mountain of the LORD, to the house of the God of Jacob, that he may teach us his ways and that we may walk in his paths.” For out of Zion shall go the law, and the word of the LORD from Jerusalem. He shall judge between the nations, and shall decide disputes for many peoples; and they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore.
(Isaiah 2:2-4 ESV)
But in the sequencing of events the emphasis in Acts is that the Messiah should suffer first. In the dream of the kingdoms of Men that Nebuchadnezzar saw the rock cut out without human hands comes only during the time of the Feet of Iron and clay period.
The exact time of restoration is not clearly known:
So when they had come together, they asked him, “Lord, will you at this time restore the kingdom to Israel?” He said to them, “It is not for you to know times or seasons that the Father has fixed by his own authority. But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.”
(Acts 1:6-8 ESV)
In the who scheme of things the Apostles preached that Jesus was the God appointed WAY.
The concept of Trinity never occurred to them. Christian’s hope very less in the ‘restoration’ message because for most of them the final destination is heaven and nothing beyond that. It seems only in the 20th C many evangelists are considering this teaching of ‘restoration’ seriously in the light of establishment of the Jews to their homeland in 1948.