Return and Gabriel (2005–2009)
During the following years both Bachman and Daub worked in sound production at their Trauma Studios in Pennsylvania for groups such as Turmoil and Living Sacrifice. Later, Bachman continued in his medical studies, while Daub kept working in the music industry. Later in the 1990s, Daub began playing drums in a female-fronted progressive metal band called Fountain of Tears.
In 2005, Joey Daub informed on his website joeydaub.com that he had begun writing new Believer material with Bachman. This announcement was reported widely, most notably through Blabbermouth.net, which called Believer a "much missed late 80s and early 90s technical thrash metal band." In an interview, Bachman explained that he moved closer to the studio near where Joey Daub lives. Daub was working on mixing Fountain of Tears' new album and invited Bachman to help: "We just got together and started playing and having fun," Bachman stated, "nothing serious, but the chemistry was still there and stuff started clicking. We wrote some tunes, played them for some people and then some of our friends in the industry said 'you guys should put this out, maybe there's one or two Believer fans still out there that wouldn't mind hearing it.'"
The band started working on an album and completed pre-production of new songs during November 2007. On October 21, 2007, Believer launched an official MySpace page. The band's catalogue was rereleased by the Polish label Metal Mind Productions. Blabbermouth.net reported the album's recording process which began on November 24, drum tracking was completed on December 30, bass was laid down on January 28, 2008, rhythm guitar tracks were completed on February 18, and on April 7 the band announced that the album would feature "some very talented guests." Ten days later on April 17, Deron Miller of CKY announced that he will be "laying down some guest solos and/or vocals" for the forthcoming Believer album. He commented that "Believer have been one of my favorite bands for 20 years so this is really exciting for me. Check out the three records they did in the '90s... All three are works of genius." On August 13, it was announced that the album would also feature guest performances by Joe Rico of the band Sacrifice, with whom Believer toured in the early 1990s, and Rocky Gray of Living Sacrifice.
On November 18, 2008, Blabbermouth.net announced Believer's signing with Cesspool Recordings, an imprint of Metal Blade Records owned by Howard Jones of Killswitch Engage. In an interview with Metalsucks.net, Bachman commented that the announcement about the band's re-activation had spread to the industry, and a staff member from Blabbermouth/Roadrunner Records suggested that they should contact Howard: "We got in touch with him and it turns out he is a big Believer fan. He knows more about the history of Believer than we do! It was really cool. So we flew him in to the studio, we worked with him over two days. Then he mentioned that he was starting this imprint with Brian Slagel from Metal Blade and he asked us if we wanted to be the first band on it." Jones forwarded the band to Slagel whom reportedly replied: "Believer? Absolutely, lets do this.'" "It was sort of an easy process for us as far as the business end of it was concerned," Bachman stated. They signed a 3-album deal with Metal Blade.
The fourth full-length studio album titled Gabriel was released on March 17, 2009, in US and Canada, and on April 9–15 elsewhere. The album line-up consists Kurt Bachman (vocals, guitar), Joey Daub (drums), Jeff King (keyboards, of Fountain of Tears fame), Kevin Leaman (guitar), and Elton Nestler (bass). Scott Laird (violin), Jim Winters (guitar) and William Keller, who played with the band previously, also contributed to the album as session musicians. An unmastered version of the song "Medwton" from the album premiered on Bam Margera's Radio Bam show on November 17. The track "Focused Lethality" was released as a single on February 13. The song is reminiscent of the band's style on their first album. The second single "Stoned" was released on March 12. The album was mostly positively received. The band played live shows after the release.