Passage
This, then, I say, and I testify in the Lord; ye are no more to walk, as also the other nations walk, in the vanity of their mind,
This, then, I say, and I testify in the Lord; ye are no more to walk, as also the other nations walk, in the vanity of their mind,
Ephesians 4:15 and, being true in love, we may increase to Him <FI>in<Fi> all things, who is the head--the Christ;
Ephesians 4:16 from whom the whole body, being fitly joined together and united, through the supply of every joint, according to the working in the measure of each single part, the increase of the body doth make for the building up of itself in love.
Ephesians 4:17 This, then, I say, and I testify in the Lord; ye are no more to walk, as also the other nations walk, in the vanity of their mind,
Ephesians 4:18 being darkened in the understanding, being alienated from the life of God, because of the ignorance that is in them, because of the hardness of their heart,
Ephesians 4:19 who, having ceased to feel, themselves did give up to the lasciviousness, for the working of all uncleanness in greediness;
The verse centers on "testify", "lord", "walk", "other", "nations", "vanity", and "mind". It is saying that the verse draws attention to "testify" and "lord", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 16's "from whom the whole body being fitly..." into verse 18's "being darkened in the understanding being alienated...", so "testify" and "lord" 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 "testify" and "lord" with trust shaped by these words, not by a vague optimism outside the passage.