It says in the Qur'an 2:183) "O you who believe, fasting is prescribed for you, as it was prescribed for those before you, so that you may guard (against evil).
2:184) For a certain number of days; but whoever among you is sick or on a journey, then (he shall fast) a (like) number of other days; and those who are not able to do it may effect a redemption by feeding a poor man; so whoever does good spontaneously it is better for him; and that you fast is better for you if you know.
2:185) The month of Ramadhan is that in which the Qur'an was revealed, a guidance to men and clear proofs of the guidance and the distinction; therefore, whoever of you is present in the month, he shall fast therein, and whoever is sick or upon a journey, then (he shall fast) a (like) number of other days; God desires ease for you, and does not desire for you difficulty, and (desires) that you should complete the number and that you should exalt the greatness of God for having guided you and that you may give thanks."
Struggling to please God. The greater, or internal Jihad is the struggle against the evil within one's own soul in every aspect of life. The lesser, or external, Jihad is the struggle against the evil of one's environment in every aspect of life.
Amr-bil-ma'rūf is a Qur'anic commandment to enjoin what is good. This is done through living by the rules of God from the Qur'an and hadith. The command to "enjoin what is good" is given in several Qur'anic verses.
Nahi-anil-munkar is a Qur'anic commandment to "forbid what is evil". This can be done by refraining from the sins mentioned by Allah in the Qur'an and the sins which the Prophet Muhammad stated in hadith. Al-munkar means "the rejected". The following verses from the Qur'an are said to command the believers to forbid what is evil:
