Paul addresses confusion about the timing of Christ's return by clarifying that the Day of the Lord has not yet come, as evidenced by the absence of the great apostasy and revelation of the man of lawlessness. His teaching about God's restraining power holding back ultimate evil until the appointed time provides comfort during present persecution while warning of future deception. The practical instruction to avoid idle believers who refuse to work demonstrates how eschatological hope should motivate present responsibility rather than passive waiting, with church discipline applied to those who disrupt community order.