And the men of Bethshemesh said, Who is able to stand before this holy LORD God? and to whom shall he go up from us?

Wesley's Notes

6:20 Who is able, and c. - That is, to minister before the ark where the Lord is present. Since God is so severe to mark what is amiss in his servants, who is sufficient to serve him? It seems to be a complaint, or expostulation with God, concerning this great instance of his severity. And to whom, and c. - Who will dare to receive the ark with so much hazard to themselves. Thus when the word of God works with terror on men's consciences, instead of taking the blame to themselves, they frequently quarrel with the word, and endeavour to put it from them.

Matthew Henry's Concise Commentary

6:19-21 It is a great affront to God, for vain men to pry into, and meddle with the secret things which belong not to them, De 29:29; Col 2:18. Man was ruined by desiring forbidden knowledge. God will not suffer his ark to be profaned. Be not deceived, God is not mocked. Those that will not fear his goodness, and reverently use the tokens of his grace, shall be made to feel his justice. The number smitten is expressed in an unusual manner in the original, and it is probable that it means 1170. They desire to be rid of the ark. Foolish men run from one extreme to the other. They should rather have asked, How may we have peace with God, and recover his favor? Mic 6:6,7. Thus, when the word of God works with terror on sinners' consciences, they, instead of taking the blame and shame to themselves, quarrel with the word, and put that from them. Many stifle their convictions, and put salvation away from them.