Treasury of Scripture Knowledge
1 Corinthians 6:18
Stay away from [any involvement in] sexual immorality. Every sin a person commits is outside [the realm] of his body; but the one who commits sexual immorality sins against his own body. [Note: Possibly this means that sex, because it requires the deepest and most complete commitment of human involvement, becomes a unique sin when its true purpose and expression are violated].
1 John 4:13
This is [one way] to know we live in [fellowship with] God and that He lives in our hearts: [It is] because He has given us His Holy Spirit [to live within us, See 3:24].