Matthew Poole and continuators on John 6:71

71 He spake of Judas Iscariot, the son of Simon : for he it was that should betray him, being one of the twelve .

This he spake of Iudas Iscariot (so called, as most think, from the name of the City where he lived) and to distinguish him from the other Iudas, the Brother of Iames, who wrote the Epistle that goeth by his Name; and is a part of Holy Writ: For

he being one of the twelve, chosen and sent out with the rest to Preach the Gospel, and impowred by Miraculous Operations to confirm the truth of it; yet it was he that was to betray Christ, as we largely read in all the Evangelists relation of the Passion. To teach us, That no Office to which God calleth us, no Gifts (except those of Special Grace) with which God blesseth any man, can secure him of an Eternal happy state; nothing can do that but a true saving Faith in Jesus Christ, with the Obedience of an Holy Life becoming the Gospel of Christ.