Both Islam and Christianity believe that God sent His messengers to lead human beings into the right path. They do differ as to how to deal with the separation between God and man caused by the sin of men, which the Bible clearly states is evident in the whole of humankind, “There is no one righteous, not even one” (Romans 3:11), for, “all have sinned and fall short of the glory of God” (Romans 3:23). In general, sin means transgression of the law of God (1 John 3:4). This law exists because God is Holy and so cannot abide with evil. It is offensive to God no matter what the sinner’s excuse or how insignificant the sin.
The Qur’an also tells us that all are guilty and unworthy to be saved. If God were to judge us all according to his rules, none of us would be saved. “If Allah were to punish men for their wrong-doing, he would not leave, on the earth, a single living creature” (Sura 16:61, see also Sura 35:45).