He married his wife, Ricka Cox around 1973, with whom he had two children, John Joel and Annie Grace.
JAG's original lineup for their 1990 debut, The Longest Road included guitarist J. Paul Brittain, guitarist and keyboardist Joel McCreight, bassist Tim Hall, drummer Chuck Connor, and Garies on lead vocals.
Their 1991 follow up The Only World in Town traded McCreight for Michael Lusk and featured additional help from drummer Chris McHugh and guitarists, Jim Williams, Dale Oliver (originally of Geoff Moore's band) and Giant's Dann Huff.
Produced by frequent CCM-session keyboardist Blair Masters, JAG's final album, Fire in the Temple, featured songs written by Garies, and the likes of Billy Smiley and Mark Gersmehl and performed by players Gordon Kennedy, Chris McHugh and Tommy Sims, all of whom were current or former members of the group Whiteheart, a band's sound to which JAG is oft-compared.
Upon his death from liver disease on August 5, 2007, Garies worked for Coach USA.