to lift up: to raise on high, and so to exalt someone to a high position of honor, status, or power
This verb means to raise something to a high place, and from there to raise a person to a high position of honor, status, or power. The physical picture of lifting up and the social picture of exalting are the same act seen at two levels, and the New Testament moves freely between them. A plainer word exists for ordinary physical lifting, such as raising the eyes or the hands (ἐπαίρω); this word leans toward the higher raising of a person's standing.
Its most frequent use is exaltation. God lifts up the lowly, seats the risen Jesus in the place of highest honor, and promises to raise up those who lower themselves before him. This drives one of the New Testament's great reversals, repeated almost word for word: whoever lifts himself up will be brought low, and whoever lowers himself will be lifted up. The lifting here is God raising a person to honor, never a person congratulating himself.
John's Gospel turns the word into a deliberate play on words. When Jesus speaks of being lifted up, he means both his physical raising on the cross and his raising into glory as one single movement, so that the word sits very close to the word for showing forth glory (δοξάζω). The image reaches back to Moses raising the bronze snake on a pole in the wilderness, so that all who looked to it would live.