en_tn_condensed/eph/03/18.md

that you might be able to understand

This is the first item which Paul says will be the result of the Christians being rooted and grounded in Christ's love. (Ephesians 3:17)

all God's holy people

"all believers in Christ"

the width, the length, the height, and the depth

"how very wise God is" or "how much Christ loves us"