For the Lord's message sounded forth from you, not only in Macedonia and Achaia, but your faith toward God [also] spread everywhere [else], so that we do not have to say anything [about you].

So, the person who rejects [this exhortation] is not [merely] rejecting what man says but God [Himself], who gives His Holy Spirit to you.

For we say this to you by [the authority of] the word of the Lord [Note: Paul was either quoting what Jesus had previously said, or was giving a revelation he had received from the Lord. See I Cor. 14:37], that we [Christians] who are [still] alive, who are left [on earth] when the Lord returns, will certainly not precede those who have fallen asleep. [Note: The point Paul is making is that the living will not be "changed" (I Cor. 15:51-52) and taken to heaven before the dead are raised].