"And after this I will return," said God (Acts 15:16). James referenced Amos, but Amos didn't use the word "return," because God had always come to Israel in clouds of heaven. St. Paul, as I said, believed Christ was the Son of God and said Christ was the one who had historically come for Israel.
Christ, having been offered once to bear the sins of many, will appear a second time (Heb 9:28). A second coming. But as with James, that is in the New Testament context of kingdom and judgment.
As Israel's age drew to a close, Christ came twice, but all through Israel's history, he had always come. Only once did God come in the form of a man, as Philippians 2:5-8 avers. Otherwise, he comes in clouds of heaven, in Spirit, invisible to the naked eye.
That's what the text says.