'Vital' in the Bible

I am the Vine; you are the branches. The one who remains in Me and I in him bears much fruit, for [otherwise] apart from Me [that is, cut off from vital union with Me] you can do nothing.

and [if you claim to] know His will and approve the things that are essential or have a sense of what is excellent, based on your instruction from the Law,

For I testify about them that they have a certain enthusiasm for God, but not in accordance with [correct and vital] knowledge [about Him and His purposes].

to the latter one an aroma from death to death [a fatal, offensive odor], but to the other an aroma from life to life [a vital fragrance, living and fresh]. And who is adequate and sufficiently qualified for these things?

so that you may learn to recognize and treasure what is excellent [identifying the best, and distinguishing moral differences], and that you may be pure and blameless until the day of Christ [actually living lives that lead others away from sin];

Then I fell down at his feet to worship him, but he [stopped me and] said to me, “You must not do that; I am a fellow servant with you and your brothers and sisters who have and hold the testimony of Jesus. Worship God [alone]. For the testimony of Jesus is the spirit of prophecy [His life and teaching are the heart of prophecy].”