Though we have good intentions they are not fulfilled because we're stuck in the enemies nets. According to Bishop Theophan the Recluse, the following are the three reasons why we remain unrepentant:
(a) The first of these reasons is that our own resolutions are not based on distrust of ourselves and a firm trust in God. Therefore we are not devoid of high opinion of ourselves, the inevitable consequence of which is always withdrawal from us of the blessed Divine help and our consequent inevitable downfall. This is why a man, who decides in himself: ‘ To-morrow I shall abandon the path of sin without fail ‘, always meets with the opposite effect— that is, instead of rising up he falls down worse than before, which is followed by downfall after downfall. God sometimes allows this to happen deliberately, in order to bring the self-reliant to the realisation of his weakness and urge him to seek Divine help, renouncing and abandoning all trust in himself, since God’s help alone can be trusted. Do you want to know, 0 man, when your own decisions will be firm and reliable? When you abandon all trust in yourself and when all your hopes are based on humility and a steadfast trust in God alone.
(b) The second reason is that in making such resolutions we mostly have in view the beauty and radiance of virtue, which attract our will, however weak and impotent it may be; and so naturally the difficult side of virtue escapes our attention. To-day this side escapes notice, because the beauty of virtue strongly attracts our will; but to-morrow, when the usual works and cares present themselves, this attraction will not be so strong, although the intention is still remembered. When desire weakens, the will also becomes weaker or relapses into its natural impotence, and at the same time the difficult side of virtue stands out and strikes the eye; for the path of virtue is by its nature hard, and is hardest of all at the first step. Now let us suppose that the man, who decided yesterday to enter upon this path, today does so; he no longer feels any support for carrying out his decision. The desire has lost its intensity, the will has weakened, nothing but obstacles are in sight—in himself, in the habitual course of his life, in the usual relationships with others. And so he decides: ‘I shall wait a while and gather my strength.” Thus he goes on waiting from day to day, and it is no wonder if he waits all his life. And yet had he started work yesterday, when the inspiring desire to mend his ways came upon him, had he done one thing or another in obedience to this desire, had be introduced into his life something in this spirit— today his desire and will would not be so weak as to retreat in the face of obstacles. There must be obstacles, but if the man had something to lean on in himself, he would have overcome them, be it with difficulty. Had he been occupied all day with overcoming them, the next day he would have felt them far less; and on the third day still less. Thus going further and further he would have become established on the right path.
(c) The third reason is that if the good of awakening from sinful sleep is not translated into practice, such awakenings do not easily come again; and even if they do come, their effect on the will is less strong than the first time. The will is no longer as quick in inclining towards following them and so, even if the resolve to do so is there, it is weak and lacks energy. Consequently, if a man was able to put off till to-morrow obedience to a stronger impulse and then lost it altogether, how much more easily will he do this a second time, and still more easily the third. And so it goes on: the more often obedience to good impulses is put off, the weaker their effect. After a time they lose their effect altogether, come and go without leaving a trace, and finally cease to come at all. The man surrenders himself to his downfall: his heart hardens and he begins to feel an aversion from good impulses. Thus delay becomes a straight road to final perdition