Look at verse 1. When Paul writes, “But concerning the times and the seasons, brethren,” it probably indicates that he was responding to a question that the Thessalonians sent to Paul through Timothy. They may have wanted to know how long they would have to wait until Jesus returned. Paul said, “But concerning the times and the seasons, brethren, you have no need that I should write to you.” It appears that he had already instructed them on the Second Coming of Jesus when he was with them, but he was willing to put this teaching from the Lord in writing.
The Spirit and Power of Elijah
They confessed that Jesus is Christ, meaning that they believed Jesus was the Messiah, but like all Jews, they also knew that Malachi said that before Messiah appeared with healing in His wings, Elijah would come first. So, they asked, “Why do the scribes say that Elijah must come first?” They did not yet understand that John had come in the spirit and power of Elijah.
This Generation
When will that day be? In verse 32 Jesus said, “But of that day and hour no one knows, not even the angels in heaven, nor the Son, but only the Father.” We don’t know the day or the hour, but we should be able to see the signs and perceive the season. Instead of trying to figure out exactly when He will return, Jesus said that we should always be ready: “Take heed, watch and pray; for you do not know when the time is.”