The New Order was the album that broke Testament into the thrash metal mainstream, with singles "Trial by Fire" (which featured a music video, as did "Nobody's Fault", which is a cover of Aerosmith) and "The Preacher". This success would only grow with their next album Practice What You Preach. The New Order was also the first Testament album to enter the Billboard 200, reaching number 136 on that chart. It was also the band's first album to include an instrumental track. The album contains many songs that the band still plays live to this day including "Into the Pit", "The Preacher", "The New Order", "Disciples of the Watch", and "Trial by Fire". "Into the Pit" is one of Testament's most frequently performed songs, having been played live 500 times (second only to "Over the Wall" from The Legacy, at 515).
Reviews for The New Order have generally been favorable. Allmusic's Alex Henderson awards the album four-and-a-half stars out of five, and claims that Testament "delivered its best offering ever" and describes it as "every bit as brutally forceful as The Legacy." He also called the album the "ideal choice."
The New Order entered the Billboard 200 album charts in August 1988, three months after its release. The album peaked at number 136 and remained on the chart for thirteen weeks, making it Testament's longest run so far. "Trial By Fire" and "The Preacher" were released as singles, but neither of them charted.
By 1990, The New Order had sold over 250,000 copies in the U.S.
In August 2014, Revolver placed The New Order on its "14 Thrash Albums You Need to Own" list.