Complex sentence: Marriage in Sikhism is seen as a union of souls, and the soul is seen as genderless, with the outward appearance of human beings (man, woman) being a temporary state.
Split into simpler sentences: Marriage in Sikhism is seen as a union of souls. In Sikhism, the soul is seen as genderless, and the outward appearance of human beings (man, woman) is a temporary state.