Albert Barnes, New Testament Commentary on Mark 3:21
“He is beside himself.
He is delirious, or deranged, The reason why this report gained any belief was, probably, that our Lord had lived among them as a carpenter; that he was poor, and unknown; and that now, at thirty years of age, he broke off from his occupations, abandoned his common employment, spent much time in the deserts, denied himself the common comforts of life, and set up his claims to be the Messiah, who was expected by all the people to come with great pomp and splendour. The charge of derangement on account of attention to religion has not been confined to our Saviour. Let a man be made deeply sensible of his sins, and spend much of his time in prayer, and have no relish for the ordinary amusements or business of life; or let a Christian be much impressed with his obligation to devote himself to God, and act as if he believed there was an eternity, and warn his neighbours of their danger; or let a minister show uncommon zeal, and waste his strength in the service of his Master, and the world is not slow to call it derangement. And none will be more ready to originate or believe the charge than an ungodly and infidel parent or brother; a self-righteous Pharisee or professor in the church. At the same time, men may endanger themselves on the bosom of the deep, or in the bowels of the earth, for wealth; or may plunge into the vortex of fashion, and folly, and vice, and break in upon the hours of repose, and neglect their duties to their family, and the demands of business, and in the view of the world it is wisdom, and proof of a sane mind! Such is the consistency of boasted reason; such the wisdom and prudence of worldly men!”
[Truly, Jesus said: “”Blessed are you when they revile and persecute you, and say all kinds of evil against you falsely for My sake. Rejoice and be exceedingly glad, for great is your reward in heaven, for so they persecuted the prophets who were before you” (Matthew 5:11-12 NKJV).]