Johnson was born and raised in London's East End on August 14, 1961 (I'm fairly sure it's Aug 61, but the 14th is a guess. Anyone know for sure?). His parents owned/operated several pubs during his childhood having the family live above them. He grew up with 3 brothers (one elder - Andy Dog - and 2 younger) one of whom (a younger one -- Any more info?? email me) died of a brain aneurysm in 1989 just prior to the Mind Bomb tour. By his own admission, he was a dreamer while in school and didn't recieve the best eduacation (dropping out of school at the age of 15). By 11 he was performing music. By 15 he was working full-time at DeWolf's studio where he realized that he could, through the use of loops, drum machines and other pieces of technology, be a completely self-sufficient solo artist.
This is a fairly common question and it's been answered about the same every time. He considers himself an agnostic (ie. One who holds the view that any ultimate reality (as God) is unknown and probably unknowable).
Johnson's family was not religious and MJ described the school that he attended as an athiest school. With this background it would be surprising for him to develop a religious sense as a child. For Mind Bomb, Johnson read many major religious texts such as the Bible, the Koran, and other religious texts. From this background he has developed a contempt for organized religion. Saying that it is being used 'as a tool for supressing humanity.' When in an AOL interview, Johnson said that he was a 'born-again agnostic' he may have been referring to a lightening of his attitude towards a celestial presence following the death of his brother ("Love is Stronger Than Death" is an example of a gentler Johnson).