By Allaah's blessing and mercy, Islaam contains the complete and perfect guidance for humanity. Allaah (SWT) said:
This day I have perfected your religion for you, have completed My favor upon you, and have chosen for you Islaam as your religion.1
Islaam did not neglect any information needed by people to achieve happiness and avoid harm, in all matters - small or large. It informs them of all that would save them from the Fire and let them into the Gardens in the Hereafter. This was the mission of all of the prophets, as declared by Muhammad :
Never was a prophet before me, but he disclosed to his people what he knew to be best for them, and warned them of what he knew to be evil for them.2
This was the mission of the Final Messenger as well, as he said:
There is nothing that would bring you closer to Jannah3 and farther from the Fire but it has been clarified [by me] to you.4
Some mushrikoon (idol worshipers) tried to mock Islaam by saying to Salmaan (), "It seems as if your prophet has taught you everything, even how to defecate!" Salmaan () responded with dignity:
"Yes indeed! He prohibited us from turning our faces or backs to the Qiblah5 when defecating or urinating, from using the right hand to cleanse ourselves, from using less than three stones to cleanse ourselves [in the absence of water], and from using animal waste or bones to cleanse with."6
With His encompassing Wisdom, Allaah (SWT) made His Final Revelation, Islaam, a universal message for all peoples at all times, without any distinction:
We have not sent you [Muhammad] but to humanity at large, to be a herald of glad tidings and a warner.7
Furthermore, this most important Message is preserved intact through the centuries, as is clearly observed today by any impartial examiner. This is a fulfillment of Allaah's promise:
It is We indeed who have sent down the thikr (the Message), and it is We who shall surely guard it [from corruption].8
We conclude then that:
a) Islaam contains the complete and perfect guidance for humanity.
b) Islaam did not neglect any information that would be needed by people to reach happiness and to avoid harm, in all matters, whether minute or large.
c) Islaam is the only guidance tailored for all peoples at all times.
d) Islaam has been preserved, and will remain intact through the ages, as the only true guidance capable of helping and saving people.