We will endeavor to point out some of the particulars in which a non-saving faith is defective, and how it comes short of a faith which does save. First, with many it is because they are willing for Christ to save them from hell, but are not willing for Him to save them from self. They want to be delivered from the wrath to come, but they wish to retain their self-will and self-pleasing. But He will not be dictated to: you must be saved on His terms, or not at all. When Christ saves, He saves from sin - from its power and pollution, and therefore from its guilt. And the very essence of sin is the determination to have my own way (Isaiah 53:6). Where Christ saves, He subdues this spirit of self-will and implants a genuine, a powerful, a lasting, desire and determination to please Him.
Again, many are never saved because they wish to divide Christ; they want to take Him as Saviour, but are unwilling to subject themselves unto Him as their Lord. Or if they are prepared to own Him as Lord, it is not as an absolute Lord. But this cannot be: Christ will either be Lord of all or He will not be Lord at all. But the vast majority of professing Christians would have Christ’s sovereignty limited at certain points; it must not encroach too far upon the liberty which some worldly lust or carnal interest demands. His peace they covet, but His "yoke" is unwelcome. Of all such Christ will yet say, "But these Mine enemies, which would not that I should reign over them, bring here, and slay them before Me" (Luke 19:27).
Also, there are multitudes who are quite ready for Christ to justify them, but not to sanctify. Some kind, some degree, of sanctification they will tolerate, but to be sanctified wholly, their "whole spirit and soul and body" (1 Thessalonians 5:23), they have no desire for. For their hearts to be sanctified, for pride and covetousness to be subdued, would be too much like the plucking out of a right eye. For the constant mortification of all their members they have no taste. For Christ to come to them as Refiner, to burn up their lusts, consume their dross, to dissolve utterly their old frame of nature, to melt their souls, so as to make them run in a new mould, they refuse. To deny self utterly, and take up their cross daily, is a task from which they shrink with abhorrence.
Adapted from Practical Christianity, 1. Saving Faith, by A.W. Pink.