The only place in the canonical New Testament where you might be told otherwise is Mark 3:21, which the popular New International Version translates: “When his family heard about this, they went to take charge of him, for they said, ‘He is out of his mind.'” Many other English translations of this verse are similar (link).
The popularity of this unflattering glimpse of the holy family is a mystery. Mark‘s original Greek is thoroughly vague. The verb translated as to take charge of (kratesai) covers both welcome and unwelcome touching, whether for healing (as at verse 1:31), or to make an arrest (as in Gethsemane, 14:46). The verb translated as he is out of his mind (exeste) similarly applies equally well to a variety of mental states, from the positive astonishment at Jesus’s teaching and miracles (for example, verse 2:12) to something negative that contrasts with sobriety or calm demeanor (2 Corinthians 5:13).
It’s even vague whether Jesus’s family is involved at all. The Greek phrase is no more specific than something like those who are close to him (hoi par’ autou). In context, Jesus’s family is one reasonable inference about Mark’s meaning, but many English translations follow the 1611 King James Version here and say his friends instead. James McGrath recently offered discussion of still other reasonable views about who might be close to Jesus (link). Regardless, whether they are friends or family or somebody else, some of those who know Jesus well are often portrayed in translated Christian literature as having prepared a physical intervention based on their appraisal that Jesus’s mental state was dodgy.
This posting puzzles out what Mark intended this verse to convey, and why a master craftsman wrote it so opaquely. Something important is at stake. Christians promoting an unflattering “factoid” about Jesus without support from the source text undercuts a widely cited heuristic used for discerning supposed facts about Jesus’s life, including whether or not Jesus was a real person who actually lived.