The Archbishop of Wales, the Most Rev Rowan Williams, made his comments during a meeting of the Church in Wales's governing body in Lampeter, west Wales.
He attacked the way sex is portrayed in the entertainment industry.
Many people today, he said, regarded sex merely as entertainment to be used for "personal gratification" and in doing so, missed out on its deeper meaning.
Using Notting Hill - a romantic comedy which emerged as the biggest -grossing British film of all time - as an example, Dr Williams said: "Forget the floppy hero and his neurotic film star beloved.
"Look at his married friends, two prosperous young lawyers - but she is paralysed and unable to have children.
"Yet every word and gesture they come out with is full of absolute mutual joy - far more erotic, I'd say, than Hugh Grant's clumsy courtship of Julia Roberts."
Children should be taught not just about the mechanics of sex, but also about deeper loving relationships that can exist between two people, he said.
"It's not just about information and the technicalities of sex but that we look at some of the great imaginative relationships with sex in literature, drama and film," the Archbishop added.
And in understanding more about "real loving marriages", he believed Christians would get on better with each other.
Dr Williams has spoken out on a number of subjects since his becoming Archbishop of Wales in February.
At his enthronement ceremony he referred to the political battles then taking place in the Assembly by saying society was "seduced" by power.