In the Sermon on the Mount, Jesus warned that even mental or verbal infringements of the commandments render one liable to Gehenna (Matt 5:20), and He said: “If your right eye causes you to sin, pluck it out and throw it away; it is better that you lose one of your members than that your whole body be thrown into hell” (Matt 5:29f.). He also held out the threat of Gehenna to any who “causes one of these little ones who believe in me to sin,” and repeated the warning already quoted above (Mark 9:42-47; Matt 18:9). In Matthew 10:28, cf. Luke 12:5, He told His disciples to fear none but God, who alone is able to cast both body and soul into Gehenna.
The last two occurrences are in Matthew 23, in our Lord’s vigorous denunciation of the Pharisees. In v. 15, He accused them of so indoctrinating any proselyte that they cause him to become twice as much a child of Gehenna as themselves. The Hebraism “child (or ‘son’) of Gehenna” means one fit for and doomed for Gehenna. In v. 33, He concluded: “You serpents, you brood of vipers, how are you to escape being sentenced to hell?”
The other NT writings, although not using the word “Gehenna,” use equivalent expressions—of judgment, wrath, fire, destruction, perdition, Tartarus, the lake of fire (q.v.)
There is evidence among the rabbis, both those of the strict school of Shammai and the more liberal school of Hillel, of beliefs that consignment to Gehenna will either result in annihilation or will be purgatorial, and therefore will be ultimately followed by blessedness. These beliefs are not explicit in the NT.
A. Edersheim, LT, II (1886), 791-796; BDB (1906), 161; SBK, IV (1928), 1029-1118; R. A. Stewart, Rabbinic Theology (1961), 157-160; NBD (1962), 390, 518, 519, 527; J. Jeremias in TDNT, I (1964), 657, 658.
International Standard Bible Encyclopedia (1915)