to behold: to look at something long and attentively, taking it in with wonder or careful notice
This is the New Testament's word for a deliberate, lingering look, not a passing glance. Where the ordinary verbs for seeing simply report that something crossed a person's eyes, this one describes fixing one's gaze on a thing and really taking it in. Its noun cousin gave us the word theater: it pictures a spectator watching intently.
That attentive quality lets the word stretch in two directions. At the plain level it is watching a crowd, studying the fields, viewing a tomb, or witnessing an event with one's own eyes. At a deeper level, especially in John's writings, the same gazing becomes the language of witness: those who beheld Jesus and saw the glory of God in him. The word does not change its core; the object of the gaze lifts it from ordinary looking to seeing revelation.
Two edges round out the range. In the passive it can mean to be looked at, that is, to be on display before an audience, the trap Jesus warns about when people do good deeds to be noticed. And because to see a person can mean to go and be with them, it can soften into paying someone a visit.