Charles Spurgeon Commentary 2 Thessalonians 1:4-5

"so that we ourselves glory in you in the churches of God for your patience and faith in all your persecutions and in the afflictions which ye endure; [which is] a manifest token of the righteous judgment of God; to the end that ye may be counted worthy of the kingdom of God, for which ye also suffer:" — 2 Thessalonians 1:4-5 (ASV)

So that we ourselves glory in you in the churches of God for your patience and faith in all your persecutions and tribulations that you endure: which is a manifest token of the righteous judgment of God,

One of the clearest proofs of the judgment to come is to be found in the present sufferings of the saints through persecutions and tribulations; for if they, for the very reason that they love God, have to suffer here, there must be a future state and time for rectifying all this that is now so wrong.