The band consists of vocalist Aaron Weiss, guitarists Michael Weiss and Christopher Kleinberg, bassist Greg Jehanian and drummer Richard Mazzotta. Though their sound is hard to classify accurately, mewithoutYou's music is generally dominated by Aaron, who, rather than singing, talks in dramatic, varied tones and pitches. The band usually strays from typical song structures, featuring effects-laden guitar, a very prominent and distorted bass tone and bombastic rhythms, resulting in a rather experimental style. 

In regard to being a Christian band, Aaron Weiss has this to say on the subject: "I don’t mind when anybody says it for my sake. It’s not like I’m offended if someone says we’re a Christian band. I just don’t think it’s true. I don’t think we live up to that calling, so I’d be reluctant to go saying that, and God knows the truth. Our hearts are very far from Jesus. No, I’m not concerned. People could say we’re a Hindu band or say we’re an atheist band—it’s not going to bother me. They can say we’re a bad band. It’s alright. No one knows what our hearts are like. It’s just, if they like the music, is their life better hearing the lyrics? Does it make a difference at all? Or is it encouraging them to go have that same self-righteous spirit that I described during my first encounter with Christianity? I don’t want to encourage that in people. I don’t want to perpetuate that Christianity. But I also have a very clear sense of mission and purpose that I believe is from God, so I don’t shy away from that either."

He has also stated that "really, it seems like we’re all on the same journey of searching for what’s true and sort of growing in our capacity to understand the subtleties of what that might be."

His brother Mike has stated that "we don't really try to claim that we are the ambassadors of that truth ourselves, or that the Bible, or the Koran, or Bawa Muhaiyaddeen are. These truths just exist, and everybody sort of has a way to know them, to experience them, to live them."

He has further said that "right now is sort of a period, especially in Aaron's life, where he's sort of revisiting [religion] and holding himself up to those teachings that there's no one religion that's going to be the only way to God."

The band was originally conceived as a side project. The Weiss brothers and Kleinberg were playing together in another band called The Operation (who released one album, 2001's There Is Hope for a Tree Cut Down, on Takehold Records), but Aaron wanted to start another band to experiment with new sounds. After picking up Rick Mazzotta on drums and Ray Tadeo on bass, Kleinberg and the Weiss brothers released their first EP (I Never Said That I Was Brave) in 2001 and shortly thereafter signed to Tooth & Nail Records after a show at Cornerstone Festival the same year. Around this time Tadeo had moved on, Daniel Pishock picked up as the bass player, and The Operation disbanded soon afterward. mewithoutYou's debut full-length album, [A→B] Life, was released in 2002. The band garnered more attention for their second release, 2004's Catch for Us the Foxes, which was produced by Brad Wood[(Matt Strang)] (Smashing Pumpkins, Fire Theft). In December of 2004 Pishock had made a decision to retire as the bassist for the band and former Operation frontman, Greg Jehanian, was selected to replace him. In 2005, mewithoutYou won mtvU's "Left Field" award for most original artist. Their third album, Brother, Sister, again produced by Wood, was released on September 26th, 2006.

mewithoutYou has released videos for "January 1979" and "Paper Hanger", from Catch for Us the Foxes, with the help of Red Van Pictures this past year, and one for "Bullet to Binary" from [A→B] Life. They have recently released a video for "Nice and Blue, Pt. 2" from Brother, Sister, directed by Shane Drake.

In late 2007, guitarist Christopher Kleinberg left the band, to pursue a degree in medicine. Pete Syoum filled in for guitar in the fall of 2007, but later Kleinberg returned to play with the band on their 2008 Summer tour since school was not in session. Kleinberg also played some shows on their, It's All Crazy! It's All False! It's All a Dream! It's Alright, tour in June 2009.

Aaron Weiss provides narration for the Forgive Durden album entitled, Razia's Shadow: A Musical which was released October 28, 2008. He also provides vocals for Norma Jean's "Memphis Will Be Laid To Waste" and Indie/Hip Hop project Bella Futuro's "70 X 7".

As of September 2008 the band has finished recording the follow-up to Brother, Sister titled, It's All Crazy! It's All False! It's All a Dream! It's Alright. The title of the album is taken from parable 518 in the book 'The Golden Words of a Sufi Sheikh" by Bawa Muhaiyaddeen. In this he writes, "It's all false, It's all a dream, It's all crazy, It's all over, It's all right, Let's see what's next". The latest album is a departure from Weiss' trademark shouting and the band's raucous grooves. The mile-a-minute rants, thick with vocal and lyrical angst, are traded for simpler melodies with lyrics about anthropomorphic food and animals. Similarly, the band has scaled back their edgier post-hardcore sound, at times trading riffs for chords and guitars for pianos and harp (once again, Timbre). Even a classical composer was called into their Fishtown, Philadelphia studio for various arrangements on several tracks. The album was produced by Dan Smith (Danielson, Sufjan Stevens) and Brian McTear and was mixed by Brad Wood.