Manifesting The Comprehensiveness of Islam and Danger of Heterodoxy
All praise is due to Allah. We praise Him, seek His assistance, ask for His forgiveness, and we repent to Him. We seek refuge in Allah from the evil of our selves and from our bad deeds. Whoever Allah guides, none can lead astray, and whoever He leaves to go astray, none can guide. I bear witness that there is no deity worthy of worship except Allah alone, Who has no partner, and I bear witness that Muhammad is His servant and messenger. Allah sent him with guidance and the religion of truth. He delivered the message, fulfilled the trust, advised the nation, and duly strove for the sake of Allah until he died. He left his nation guided to the right path that is as bright as daylight; thus, whoever deviates from this path is doomed to perdition. By means of it, he made clear what the Muslim nation needs in all its affairs. It is so clear that Abu Dharr (may Allah be pleased with him) said: “The Prophet (may Allah’s peace and blessings be upon him) did not even leave a bird flapping its wings in the sky except that he mentioned to us knowledge regarding it.”
A polytheist once told Salmān al-Fārisi (may Allah be pleased with him): “Your Prophet taught you even how to relieve yourselves!” He replied: “Yes, He forbade us from facing the Qiblah [direction of prayer] while relieving ourselves, or to clean our private parts with less than three stones, or to use the right hand to clean the private parts, or to use dung or bones to clean them.”
Indeed, you can see that Allah has clarified in the Qur’an all fundamentals and subdivisions of Islam. He explained in details all types of monotheism, and even the etiquette of assemblies and asking permission to enter places; Allah says:
{O you who believe, when you are told to make room in the assemblies, (spread out and) make room. Allah will give you (ample) room (from His mercy)}
{O you who believe, enter not houses other than your own, until you have asked permission and greeted those it them; that is better for you, in order that you may remember* And if you find no one therein, still, enter not until permission has been given to you. And if you are asked to go back, go back, for it is purer for you. And Allah is All-Knowing of what you do.}
{And women of post-menstrual age who have no desire for marriage – there is no blame upon them for putting aside their outer garments [but] not displaying adornment}
{O Prophet, tell your wives and your daughters and the women of the believers to bring down over themselves [part] of their outer garments. That is more suitable that they will be known and not be abused. And Allah is All-Forgiving, Most Merciful.}
{And it is not righteousness to enter houses from the back, but righteousness is [in] one who fears Allah. And enter houses from their doors. And fear Allah that you may succeed.}
There are many other verses that manifest the comprehensiveness and perfection of this religion, which stands needless to any addition, just as it is not liable to any deficiency.