From Rolling Stone:
This gospel-rock hymn featured the New Jersey Mass Choir. Said Jones, “I’ll always remember them getting in a circle before we did it and everyone saying the Lord’s Prayer.” That probably didn’t happen with “Hot Blooded” — but this became Foreigner’s biggest hit.
From allmusic, reviewing the album:
Despite contributing a few killer riffs to Foreigner‘s ’70s canon, guitarist/keyboardist Mick Jones isn’t known for his six-string abilities. His biggest strength is his knack for melody as a songwriter, keyboardist, and producer… Of course, vocalist/songwriter Lou Gramm is indispensable as the band’s golden-throated frontman. Jones largely guided things behind the studio console, but a co-producer usually helped, such as Alex Sadkin on this album. “I Want to Know What Love Is” became Foreigner’s first and only number one single, and it’s not hard to see why. Its dreamy, hypnotic feel is due in part to Gramm’s soulful lead vocals and the New Jersey Mass Choir’s background vocals. Jennifer Holliday and the Thompson Twins‘ Tom Bailey help out as well.