Jn.3:8 "The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit.”
"Regarding instant conversions and forsaking of sin, it is quite true that instantaneous regeneration of the mind is not a common phenomenon, especially in the present day; but it is also true, that of all remarkable moral recoveries that do occur, (alas! too few at best,) almost all are of this kind.
It is quite true that the upward effort of the will, when it exchanges the madness of passion for the perceptions of reason, are toilsome and, if successful, long in coming; and if all transformations of conscience were of the deliberate and reasonable sort, philosophers could not say too much about their infrequency and slowness. But the process springs from a higher and more powerful source; the persuasion is conducted by some new and intense affection, some fresh and vivid reverence, followed, not led, by the conscience and reason. The weeds are not painfully plucked up by the cautious hand of tillage, reckoning on its fruits, but rather burnt out by the blaze of a divine shame and love. And sometimes the soul is vividly presented with some sublime object, that until then was veiled, but now the veil is pierced as by a flash from Heaven with an instant awe and veneration that is sometimes intense enough to fuse the fetters of habit and drop them to the earth from where they were forged.
It is quite true that such a change cannot be expected, -- that to calculate on it is inexpressibly perilous; for the deeper movements of the soul shrink back from our computations, and refuse to be made the tools of our prudence, and insist on coming unobserved or coming never; and he that reckons on them sends them into banishment, and only shows that they are and must be strangers to his barren heart.
The possibility and reality of such changes, we must remember, like all changes of the affections, they neither come at the direct command of our will, nor descend on those who watch for external influences to produce them. Now some go and try this and try that, and say, 'lo here!' and 'lo there!' But they find that 'the Kingdom of God comes not by observation." And if we are wanting to be holy for the sake of being happy, we can be assured of neither; unless first the crust of our selfish nature is broken by affliction, and bending the head upon the shrine of sorrow, the cry with a contrition that forgets to be happy, -- a cry that, it may be, the Divine Spirit will not despise." Martineau.