Moses was so right on the mark when he cried out, “I cannot carry all these people by myself; the burden is too heavy for me!” (see Numbers 11:14)
It takes a confidently humble man to ask for help (see Numbers 12:3). But God gives more grace to that humble person, while He stands aloof from those know-it-alls and those I-can-do-it-all-by-myselfs.
God anointed leaders to assist Moses. He took the same Spirit that was on Moses and imparted it to those 70 leaders. But—note this carefully—the Spirit on Moses was not at all diminished!
Moses’ responsibility was to pick the 70 “who are known to you as leaders” (11:16), then the Lord placed His Spirit on them (vv. 17 and 25). There were 70 who prophesied but Moses correctly desired “that all the Lord’s people were prophets and that the Lord would put His Spirit on them” (v. 29).
Leadership is necessary, and it is meant to be shared. From the senior leader, this requires (1) humility, (2) responsibility, and (3) willingness.