The word “judgment” can refer to the sentence God imposes on people after he has weighed their actions; in this case the term inevitably has a negative loading of condemnation and punishment. The term can also refer to the fact that a judge is engaged in his task (without reference to his findings in any given case); in that case, the term carries no implicit danger, though his subsequent findings certainly may. It is a considerable stretch to insist that the first understanding would be accurate in relation to the church (= house) of the Lord. This church, after all, comprises the elect, persons sanctified by the Spirit and washed with Jesus’ blood (1 Peter 1:2; 1 Peter 2:9–10). The second understanding fits the context far better, with the Lord pictured as seated on his judgment seat and beginning his task.
17 For it is time for judgment to begin at the household of God; and if it begins with us, what will be the outcome for those who do not obey the gospel of God?