[Translating this song is literally impossible. Lisa Gerrard sings in an invented language that has no relation to any language ever spoken. The technique is called glossalalia or idioglossia. She makes up sounds that almost appear to be words, which is called euphonia, but they are not actually words at all. They are meaningless phonemes. From the Wikipedia page on Lisa Gerrard:

'She received a Golden Globe Award for the music score to the film Gladiator, on which she collaborated with Hans Zimmer on such songs as "Now We Are Free." With respect to such work she has said, "I sing in the language of the Heart. It's an invented language that I've had for a very long time. I believe I started singing in it when I was about 12. Roughly that time. And I believed that I was speaking to God when I sang in that language."[1]'

'Lisa sings many of her songs, such as "Now We Are Free", "Come Tenderness", "Serenity", "The Valley of the Moon", "Tempest", "Pilgrimage of Lost Children", "Coming Home" and "Sanvean" in idioglossia.'

'An idioglossia is an idiosyncratic language invented and spoken by only one person or very few people. Most often, idioglossia refers to the "private languages" of young children'

Another way of saying this is that she sings gibberish. She has used idioglossia in virtually all her songs since she first joined the band Dead Can Dance in the early 80's. Feel free to research Lisa Gerrard and/or Dead Can Dance. You will see that I am telling the truth. I have heard many of her songs, and I love them to pieces, but they simply do not contain any actual words, in any actual language.]

It seems to be the text which the singer used as inspiration for her glossolalia. So, it actually is the closest in meaning one could get. I'm not sure whether this even should be added as a translation, but it is the best translation possible.