But it was established upon Scriptural substantiation in word and in power.
Mat. 1:22; 2:5,15,17,18; 3:3; 4:4,6,7,10,14,15; 5:17,18,33,38,43; 8:4,17; 9:13; 11:10; 12:3,5,17-21,40,41; 13:14,15,35; 14:3,4,7-9;19:4,5,17-19; 21:4,5,13,16,42; 22:24,29,31,32,37,39,43,44; 23:35;24:15; 26:24,31,54,56; 27:9,10,35; Mark 1:2,44; 7:3,10; 9:12,13; 10:4,5; 11:17; 12:10,19,24,26 13:14; 14:21,47,49; 15:28; Lk. 2:22,23.24; 3:4,5,6; 4:4,6-8,10,12,16,17,18,20,25-27; 5:14; 7:27; 8:10; 10:26,27; 16:29,31; 18:20,31; 19:46; 20:17,18, 28,37,42,43; 22:37; 23:30; 24:25.27,32,44,45,46; Jn. 1:45; 2:17,22; 3:14; 5:39,45-47; 6:31,45; 7:19,22,23,38,42,51,52; 8:5,17; 9:26; 10:34,35; 12:14,15,38-41; 15:25; 17:12; 19:24,28,36,37; 20:9,31; 21:24; Acts 1:20; 2:16-21,25-28,34,35; 3:22,23,25; 4:11,25,26; 7:3,7,27,28,32,33,37,40,42,43,49,50,53; 8:28,30,32,33; 10:43;13:15,27,29,33,39; 15:5,15-17,21; 17:2,11; 18:13.24,28; 21:20,24; 22:12; 23:3,5; 24:14; 26:22; 28:23,26,27; Rom 1:2,17; 2:10-21,31; 4:3,7,17,18,23,24; 5:13; 7:1-3,7,12,14,16; 8:4,36; 9:4,9,12,13,15,17,25-29,33; 10:11,15,19; 11:2-4,8,9,26,27; 12:19,20; 13:8-10; 14:11; 15:3,4,9-12,21; 16:16,26,27; 1Cor. 1:19,31; 2:9; 3:19,20; 4:6; 6:16; 7:39; 9:9,10; 10:7,11,26,28; 14:21,34; 15:3,4,32,45,54,55; 2Cor. 1:13; 2:3,4; 3:7,15; 4:13; 6:2;16; 7:12; 8:15; 9:9; 10:17; 13:1; Gal. 3:6,8,10-13; 4:22,27,30; 5:14; Eph. 3:3,4; (cf. 2Pt. 3:16); Eph. 4:8; 5:31; 6:2,3; (cf. Dt. 5:16); Col. 4:16; 1Thes. 5:27; 1Tim. 5:18; 2Tim. 3:14,16,17; Heb. 1:5,7-13; 2:5-8,12,13; 3:7-11,15; 4:3,4,7; 5:5,6; 6:14; 7:17,21,28; 8:5,8-13; 9:20; 10:5-916,17,28,30,37; 11:18; 12:5,6,12,26,29; 13:5,6,22; James 2:8,23; 4:5; 1Pet. 1:16,24,25; 2:6,7,22; 3:10-12; 5:5,12; 2Pet. 1:20,21; 2:22; 3:1,15,16; 1Jn. 1:4; 2:1,7,8,12,13,21; 5:13; Rev. 1:3,11,19; 2:1,8,12,18; 3:1,7,12,14; 14:13; 19:9; 21:5; 22:6,7;10,18,19 (Note: while the Bible reveals that there is revelation which is not written down, (2Cor. 12:4; Rv. 10:4)
The scriptures chosen by the council in 382AD didn't contain any instruction on how, what, or why and so it was lost over time.
What writings became most universally established were essential due to their enduring heavenly qualities and attestation, like as men of God were, while what was lost was due to the lack of such, except among a relative few such as the Gnostics.
Thus derivative works such as the Qur'an and the Book of Mormon much depend upon such books for their degree of apparent validity. It was not The Vedas or the book of Jasher than the devil quoted from in seeking to seduce Christ.