This is a great mystery: but I speak concerning Christ and the church.
Ephesians 5:32
King James Version (public domain)
Traditionally attributed to Paul · 1st century AD · Thirteen epistles of the New Testament are traditionally attributed to him
Context
30For we are members of his body, of his flesh, and of his bones.
31For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh.
32This is a great mystery: but I speak concerning Christ and the church.
33Nevertheless let every one of you in particular so love his wife even as himself; and the wife see that she reverence her husband.