From a Christian perspective...

[Kadagar_AV]

From the Bible: Matthew 19 : 4-6 (KJV)

19:4 And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female,
19:5 And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?
19:6 Wherefore they are no more twain, but one flesh. What therefore common sence hath joined together, let not man put asunder.

I can agree to this if you replace "god" with "common sence".

I love my GF and want nothing else. She completes me...