Do the Murji'ah believe that whoever says "there is no god but Allah" will not be harmed and will not be touched by the Fire, even if he does not pray, fast, or give zakat?

The specific author of the saying "No sin harms with faith" is unknown. The saying is attributed to some of the extremist Murji'ah, and its implication is that one who abandons prayer, zakat, and fasting is not subject to divine warning. This is a form of disbelief that involves denying the texts of warning. As for the Murji'ah among the jurists, they agree with the Ahl al-Sunnah that the perpetrator of a major sin deserves blame and punishment and is subject to Allah's will. Sheikh al-Islam Ibn Taymiyyah warned against the danger of this saying, considering it blatant disbelief if it implies that abandoning deeds causes no harm. He stated that the jurists who hold that faith is a verbal declaration agree with the scholars of Sunnah that those who commit sins are subject to blame and warning, and that some of them will enter Hell but none will abide therein forever. The widespread association of this saying with the Murji'ah has led to a clear corruption, which is the assumption by some that they are free from Irja' (Murji'ism) despite adopting some of its other tenets.