The Buddha explains the importance of accomplishment in virtue, aspiration, self-development, view, and diligence in the development and cultivation of the noble eightfold path.
Sīlasampadādi suttapañcaka - Five Discourses Beginning With Accomplishment in Virtue
45.50
"Just as, bhikkhus, the forerunner and the precursor of the sunrise is the dawn; so too, bhikkhus, the forerunner and precursor for the arising of the Noble Eightfold Path in a bhikkhu is the accomplishment in virtue. For a bhikkhu accomplished in virtue, it is to be expected that he will develop and extensively cultivate the Noble Eightfold Path.
45.51
For a bhikkhu accomplished in aspiration, it is expected that he will develop and extensively cultivate the noble eightfold path.
45.52
For a bhikkhu accomplished in self-development, it is expected that he will develop and extensively cultivate the noble eightfold path.
45.53
For a bhikkhu accomplished in view, it is expected that he will develop and extensively cultivate the noble eightfold path.
45.54
For a bhikkhu accomplished in diligence, it is expected that he will develop and extensively cultivate the noble eightfold path."