3:7 the knowledge of the truth. First Timothy 2:4 uses this same phrase, equating it with being saved. Here Paul identified those women (v. 6) and men who were often jumping from one false teacher or cult to another without ever coming to an understanding of God’s saving truth in Jesus Christ. The present age, since the coming of Jesus Christ, has been loaded with perilous false teaching that can’t save, but does damn (cf. vv. 14,16,17; 1 Tim. 4:1).
MacArthur, John Jr: The MacArthur Study Bible. electronic ed. Nashville : Word Pub., 1997, c1997, S. 2 Ti 3:7

Notes:

4 ewho desires all men to be saved fand to come to the knowledge of the truth.
e Ezek. 18:23, 32; John 3:17; 1 Tim. 4:10; Titus 2:11; 2 Pet. 3:9
f [John 17:3]
The New King James Version. Nashville : Thomas Nelson, 1982, S. 1 Ti 2:4

6 For fof this sort are those who creep into households and make captives of gullible women loaded down with sins, led away by various lusts, 7 always learning and never able gto come to the knowledge of the truth.

f Matt. 23:14; Titus 1:11
g 1 Tim. 2:4
The New King James Version. Nashville : Thomas Nelson, 1982, S. 2 Ti 3:6-7
14 But you must scontinue in the things which you have learned and been assured of, knowing from whom you have learned them, 15 and that from childhood you have known tthe Holy Scriptures, which are able to make you wise for salvation through faith which is in Christ Jesus.
16 uAll Scripture is given by inspiration of God, vand is profitable for doctrine, for reproof, for correction, for 3instruction in righteousness, 17 wthat the man of God may be complete, xthoroughly equipped for every good work.
s 2 Tim. 1:13; Titus 1:9
t Ps. 119:97–104; John 5:39
u [2 Pet. 1:20]
v Rom. 4:23; 15:4
3 training, discipline
w 1 Tim. 6:11
x 2 Tim. 2:21; Heb. 13:21
The New King James Version. Nashville : Thomas Nelson, 1982, S. 2 Ti 3:14-17

Now the Spirit 1expressly says that in latter times some will depart from the faith, giving heed ato deceiving spirits and doctrines of demons

1 explicitly
a 2 Tim. 3:13; Rev. 16:14
The New King James Version. Nashville : Thomas Nelson, 1982, S. 1 Ti 4:1