Jamieson, Fausset and Brown on 1 Peter 4:7

7. Resuming the idea in 1Pe 4:5.

the end of all things--and therefore also of the wantonness (1Pe 4:3, 4) of the wicked, and of the sufferings of the righteous [Bengel]. The nearness meant is not that of mere "time," but that before the Lord; as he explains to guard against misapprehension, and defends God from the charge of procrastination: We live in the last dispensation, not like the Jews under the Old Testament. The Lord will come as a thief; He is "ready" (1Pe 4:5) to judge the world at any moment; it is only God's long-suffering and His will that the Gospel should be preached as a witness to all nations, that induces Him to lengthen out the time which is with Him still as nothing.

sober--"self-restrained." The opposite duties to the sins in 1Pe 4:3 are here inculcated. Thus "sober" is the opposite of "lasciviousness" (1Pe 4:3).

watch--Greek, "be soberly vigilant"; not intoxicated with worldly cares and pleasures. Temperance promotes wakefulness or watchfulness, and both promote prayer. Drink makes drowsy, and drowsiness prevents prayer.

prayer--Greek, "prayers"; the end for which we should exercise vigilance.