In the first reading (1 Thessalonians 4:9-11), the connection is very clear and basic:
We urge you, brothers and sisters,
to progress even more,
and to aspire to live a tranquil life,
to mind your own affairs,
and to work with your own hands,
as we instructed you.
In the Gospel (Matthew 25:14-30), our Lord tells us the Parable of the Talents, in which good servants use what they have been given in order to produce more, while the bad servant refuses to use what he has been given.
The message is plain: God has given us many good things, which we are to use to create even more good things.
But the ultimate rewards for the good servants’ work are not the fruits of the labor in themselves, but rather the endowment of greater responsibilities as a result of their faithful stewardship: spiritual responsibilities “in (their) Master’s joy.”
May we be faithful to the true good of what God has given us and faithful to what God has given us to do.