Love is the key.
If there’s anything “deep” in scripture that needs comprehension it’s the love of Christ:
Ephesians 3:17-19 KJV
[17] That Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, [18] May be able to comprehend with all saints what is the breadth, and length, and depth, and height; [19] And to know the love of Christ, which passeth knowledge, that ye might be filled with all the fulness of God.
Because we will be in this condition until we are changed into the heavenly:
1 Corinthians 13:12-13 KJV
[12] For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known. [13] And now abideth faith, hope, love, these three; but the greatest of these is love.
So we must endeavor to understand the love of God and spread it on the earth like salt. Because:
Matthew 22:37-40 KJV
[37] Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. [38] This is the first and great commandment. [39] And the second is like unto it, Thou shalt love thy neighbour as thyself. [40] On these two commandments hang all the law and the prophets.