Paul said to the Corinthians, “I have espoused you to one husband, that I may present you as a chaste virgin to Christ” (2 Corinthians 11:2).

“For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh. This is a great mystery: but I speak concerning Christ and the church” (Ephesians 5:31-32).

While in this case Paul was speaking of the corporate body being the Bride of Christ, there are many instances where he used marriage language to describe individual saints being in Christ and Christ being in saints.

“Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates” (2 Corinthians 13:5).
“What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own” (1 Corinthians 6:19).

“What? know ye not that he which is joined to an harlot is one body? For two, saith he, shall be one flesh. But he that is joined unto the Lord is one spirit” (1 Corinthians 6:16-17).