Passage
being darkened in understanding, estranged from the life of God by reason of the ignorance which is in them, by reason of the hardness of their hearts,
being darkened in understanding, estranged from the life of God by reason of the ignorance which is in them, by reason of the hardness of their hearts,
Ephesians 4:16 from whom the whole body, fitted together, and connected by every joint of supply, according to [the] working in [its] measure of each one part, works for itself the increase of the body to its self-building up in love.
Ephesians 4:17 This I say therefore, and testify in [the] Lord, that ye should no longer walk as [the rest of] the nations walk in [the] vanity of their mind,
Ephesians 4:18 being darkened in understanding, estranged from the life of God by reason of the ignorance which is in them, by reason of the hardness of their hearts,
Ephesians 4:19 who having cast off all feeling, have given themselves up to lasciviousness, to work all uncleanness with greedy unsatisfied lust.
Ephesians 4:20 But *ye* have not thus learnt the Christ,
The verse centers on "darkened", "understanding", "estranged", "life", "reason", "ignorance", and "hardness". It is saying that the verse draws attention to "darkened" and "understanding", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 17's "This I say therefore and testify in..." into verse 19's "who having cast off all feeling have...", so "darkened" and "understanding" belong inside that flow. In Ephesians context, the local focus is grace, union with Christ, the church, and new creation.
A plain takeaway is to answer the verse's own emphasis on "darkened" and "understanding" with trust shaped by these words, not by a vague optimism outside the passage.