They did not need to hear about the day or the hour. Why? Because it was going to come like a thief. What thief sends an RSVP before he shows up? Paul does expect God to be the one who keeps believers in one piece until he comes. . . He, nonetheless, exhorts them with simple and direct instruction about how to live. Our obedience is the means by which he keeps us.
I'd never noticed that, as we are challenged to watchfulness, Paul revisits some of the spiritual armor described in Ephesians 6:11ff. Put on the breastplate of faith and love and the helmet of the hope of salvation.
The staccato nature of the next commands adds to the force like a driving drumbeat intensifies music. Most of them are positive and encouraging, especially 1 Thess. 5: 16-22. God's will for me is to rejoice, to pray and to be thankful. Negative people don't do that.
There is a great greek word here: "oligopsychos" or small-souled. What a descriptive word for discouragement. When I am discouraged my soul shrinks. Encourage the small-souled person!