remembering before our God and Father your work of faith and labor of love and steadfastness of hope in our Lord Jesus Christ. (1 Thessalonians 1:3 - ESV)
Now Paul is getting into the specifics on why he is thankful to God for these Thessalonians. Notice the "triad" of things he is thankful for...
1. Faith -- Displayed in Work.
2. Love -- Displayed in Labor
3. Hope -- Displayed in Steadfastness.
This is not the first (or last) time that Paul mentions these three together: Faith, Hope, and Love. In 1 Corinthians chapter 13, he ends by pointing these three out, the order is different here, but the same three are mentioned. For the Corinthians, Paul may have ended on Love because that is what they were most needing to hear about, and it truly is the greatest of these. For the Thessalonians, Paul may have ended on Hope, because that is the place where they were in most need of encouragement.
Faith was displayed in work. This is actions and behaviors. Things that the Thessalonians were doing.
Love was displayed in labor. This is not the same Greek word as work... This one is focused on the sweating intensity of the actions being accomplished. The Love was not displayed primarily in the specific actions, but in the exerted effort in those actions.
Hope in our Lord Jesus Christ is displayed in steadfastness... Keeping at it!