What is the relationship of sex and spirituality?

A strange combination it seems but one that evokes huge responses. Is there something called sacred sex! Or is celibacy the only path for the true seeker. It is ultimately a personal choice that people must make, not forgetting that the spiritual practice of celibacy was and is considered to be a profound even crucial aspect of spiritual life by the Christians, Buddhist and Hindus alike. For it is foolish to underestimate the overwhelming power that the sexual instinct possesses to create complex delusions and illusions! Understand and be aware of this power fully before accepting or rejecting it.