After touring in support of its previous studio album, The New America (2000), Gurewitz re-joined Bad Religion in 2001 after a seven-year hiatus.

[5] The Process of Belief features one of Bad Religion's well-known songs "Sorrow", the band's first to chart in the US in six years, since "A Walk" (from 1996's The Gray Race).

[9] In May 2001, it was announced that drummer Bobby Schayer had sustained an inoperable rotator cuff problem, and had left the band as a result.

[15] Billy Joe Bowers handled recording, while Jeff Mosis and Philip Brousard acted as assistant engineers.

[14][20][22] The opening guitar riff in "The Lie" recalled on the one heard in "I Want to Conquer the World", a track from the band's fourth studio album No Control (1989).

[19] In August 2001, The Process of Belief was delayed from October 2001 to early 2002, which Bentley said was due to the Epitaph's aversion to releasing albums during the holiday season.

[35] "Broken" was released as a single on April 22, 2002; the CD version featured the non-album track "Shattered Faith", "Supersonic", and the music video for "Sorrow".

[40] In April and May 2003, the band embarked on a US west coast tour, with support from Sparta and Snapcase,[41] and headlined the Slam City Jam.

[47] RTÉ reviewer Harry Guerin said that despite the band members being double the age of modern acts, the album "finds them growing old gracefully and highlights how much a new generation needs their open-your-eyes anthems.

"[52] Entertainment Weekly write Jim Farber said the album had "catchier melodies and more breathlessly clever wordplay" than the band's previous releases.

Launch's Rob O'Connor called it "a MY-T-FINE punk rock album, chock full of swirling harmonies", though there was "no real surprises here".

[17] Phil Udell of Hot Press wrote that the band come across as "sounding as fresh and inspired as in their early days ... [with] sweet harmonies and a passionate belief in the power of music.

"[53] Rolling Stone writer Tom Moon said the album had "fourteen throttling songs designed to remind Sum 41's worshippers about the oft-neglected cerebral side of punk.

"[51] Slant Magazine contributor Aaron Scott found the album to be "supercharged with Gurewitz’s solid production and enough old school Bad Religion hooks to begin healing years of perceived misdirection," however, it was "not a big enough band-aid to cover all the cuts of time.

"[46] Pitchfork's Rob Mitchum found that on occasion, Graffin and Gurewitz display a "strong hook-writing ability"; however, the majority of the album was "indistinguishable from anything post-No Control".