For instance, if a Muslim is sick and can not fast during the month of Ramadhan without incurring bodily harm to himself, then even though this is one of the five pillars of Islam , he is not mandated to fast. In fact he is encouraged not to fast. The law allows for leniency in this, and most other cases.
Muslims are taught that each good deed is multiplied by Allah Almighty till it becomes the equivalent of anywhere from ten up to seven hundred similar good deeds (sometimes more). An evil deed, however, is either counted as a single evil deed or is forgiven by Allah.
A Muslim is further taught that as long as there is life there is hope. So long as death has not yet overcome him, he can still repent from his evil deeds and, if his intentions are sincere, Allah is willing to forgive all of his past evil deeds no matter if they exceed the drops of water in the ocean.
Islam teaches Muslims that God holds them responsible for their INTENTIONS and not necessarily for their DEEDS. This is revealed by the prophet Muhammad (pbuh) in the following saying which was narrated by Umar ibn al-Khattab in Sahih Al-Bukhari:
"The Prophet (pbuh) said, "O people! The reward of deeds depends upon the intentions, and every person will get the reward according to what he has intended. So, whoever emigrated for Allah and His Messenger, then his emigration was for Allah and His Messenger, and whoever emigrated to achieve a worldly benefit or for a woman to marry, then his emigration was for that which he emigrated for".
"The good deed and the evil deed are not alike. Repel the evil deed with one which is better" The noble Qur'an, Fussilat(41):34
"Verily! Allah does not forgive that a partner should be ascribed unto Him. He forgives (all) save that to whom He will. Whoso ascribes partners to Allah, he has indeed invented a tremendous sin." The noble Qur'an, Al-Nissa(4):48.
"Whatever of misfortune strikes you, it is what your right hands have earned. And He forgives much." The noble Qur'an, Al-Shurah(42):30
"And those who, when they do an evil thing or wrong themselves, remember Allah and implore forgiveness for their sins. Who forgives sins save Allah only? and they do not knowingly repeat (the wrong) they did. The reward of such will be forgiveness from their Lord, and Gardens underneath which rivers flow, wherein they will abide for ever, a bountiful reward for workers!" The noble Qur'an, A'al-Umran(3):135-136.
"He knows the treachery of the eyes, and that which the chests do hide." The noble Qur'an, Ghafir(40):19.
"He is the One that accepts repentance from His Servants and forgives sins: and He knows all that you do." The noble Qur'an, Al-Shurah(42):25.
"The likeness of those who spend their wealth in Allah's way is as the likeness of a grain which grows seven ears, in every ear a hundred grains. Allah gives manifold increase to whom He will. Allah is All Embracing, All Knowing." The noble Qur'an, al-Bakarah(2):261
"Say: My slaves who have been prodigal to their own hurt! Despair not of the mercy of Allah, Who forgives all sins. Lo! He is the Forgiving, the Merciful. Turn unto Him repentant, and surrender unto Him, before there comes unto you the doom, when you cannot be helped. And follow the better (guidance) of that which is revealed unto you from your Lord, before the doom comes on you suddenly when you know not, Lest any soul should say Alas, my grief that I was unmindful of Allah, and I was indeed among the scoffers! Or should say: if Allah had but guided me I should have been among the dutiful! Or should say, when it sees the doom: Oh, that I had but a second chance that I might be among the righteous! (But now the answer will be): Nay, for My revelations came unto you, but you denied them and were scornful and were among the disbelievers." The noble Qur'an, Al-Zumar(39):53-59.
Abu Hurairah narrated that Allah's messenger (pbuh) said
"When Allah completed the creation, He wrote in His Book which is with Him on His throne: Verily, 'My Mercy has overcome my Anger'." Narrated in Sahih Al-Bukhari.
Abu Hurairah furhter narrated : I heard Allah's messenger (pbuh) saying:
"Allah has divided His Mercy into one hundred parts, and He kept ninety nine parts with Him and sent down one part on the earth, and because of that one single part, His creatures are merciful to each other, so that even the mare lifts up it's hoof away from it's baby animal, lest it should trample it." Narrated in Sahih al-Bukhari.