What greater assurance could Paul have given them about their future than to assert, ‘and so we will always be with the Lord’ (4:17b)? Their questions and uncertainties about the future are swallowed up in that word, always. Those who die in Christ are with Him now, they will be with Him when He comes, and they will be with Him always. The same guarantee is offered to those who are alive. One can find no greater assurance than to hear that the Lord Himself wants nothing more than for His children to always be with Him.
— Mark Howell, Exalting Jesus in 1 & 2 Thessalonians, 123.