How is it that so-called monotheistic religions have theories and practices that refute the very basis of their belief?

Praise be to Allaah.  

Allaah is the Most Merciful, Most Compassionate, and He is the most Merciful of those who show mercy. His Mercy encompasses all things. Allaah says (interpretation of the meaning): 

“and My Mercy embraces all things”

[al-A’raaf 7:156] 

In Saheeh Muslim it is narrated from Abu Hurayrah that the Prophet (peace and blessings of Allaah be upon him) said: “Allaah has one hundred parts of mercy, of which He sent down one between the jinn, mankind, the animals and the insects, by means of which they are compassionate and merciful to one another, and by means of which wild animals are kind to their offspring. And Allaah has kept back ninety-nine parts of mercy with which to be merciful to His slaves of the Day of Resurrection.” 

Muslim, al-Tawbah, 6908. 

It was narrated that ‘Umar ibn al-Khattaab said: “Some prisoners were brought to the Messenger of Allaah (peace and blessings of Allaah be upon him), and there was a woman among the prisoners who was searching (for her child). When she found her child she embraced him and put him to her breast. The Messenger of Allaah (peace and blessings of Allaah be upon him) said to us, ‘Do you think that this woman would throw her child in the fire?’ We said, ‘No, by Allaah, not if she is able not to.’ The Messenger of Allaah (peace and blessings of Allaah be upon him) said, ‘Allaah is more merciful to His slaves than this woman is to her child.’”  

Agreed upon. Al-Bukhaari, 5653; Muslim, 6912. 

One aspect of the mercy of Allaah to His slaves is that He sent the Messengers and revealed the Books and laws to organize their lives according to the ways of wisdom, far removed from hardship and difficulty. Allaah says (interpretation of the meaning): 

“And We have sent you (O Muhammad) not but as a mercy for the ‘Aalameen (mankind, jinn and all that exists)”

[al-Anbiya’ 21:107] 

The mercy of Allaah is what will admit His believing slaves to Paradise on the Day of Resurrection. No one will ever enter Paradise because of his deeds alone, as the Prophet (peace and blessings of Allaah be upon him) said: “No one’s deeds will ever admit him to Paradise.” They said, “Not even you, O Messenger of Allaah?” He said, “No, not even me, unless Allaah shower me with His Mercy. So try to be near to perfection. And no one should wish for death; he is either doing good so he will do more of that, or he is doing wrong so he may repent.” 

Narrated by al-Bukhaari, 5349; Muslim, 7042 

Praise be to Allaah.

When Iblees refused to prostrate to Adam, Allaah expelled him from heaven and the curse of Allaah is upon him until the Day of Resurrection.  Allaah said to him: 

“Then get out from here; for verily, you are outcast.

And verily, My Curse is on you till the Day of Recompense”

[Saad 38:77-78 – interpretation of the meaning] 

Then he asked Allaah to grant him respite until the Resurrection, and He granted him that: 

“(Iblees) said: ‘Allow me respite till the Day they are raised up (i.e. the Day of Resurrection).’

(Allaah) said: ‘You are of those respited’”

[al-A’raaf 7:14-15 – interpretation of the meaning] 

When Iblees felt safe from destruction, he rebelled and transgressed: 

“(Iblees) said: ‘Because You have sent me astray, surely, I will sit in wait against them (human beings) on Your straight path.

Then I will come to them from before them and behind them, from their right and from their left, and You will not find most of them as thankful ones (i.e. they will not be dutiful to You)’”

[al-A’raaf 7:16-17 – interpretation of the meaning] 

When Iblees said that, Allaah said to him: 

“(Allaah) said: ‘Go, and whosoever of them follows you, surely, Hell will be the recompense of you (all) an ample recompense.

And befool them gradually those whom you can among them with your voice (i.e. songs, music, and any other call for Allaah’s disobedience), make assaults on them with your cavalry and your infantry, share with them wealth and children (by tempting them to earn money by illegal ways usury, or by committing illegal sexual intercourse), and make promises to them.’ But Satan promises them nothing but deceit.

‘Verily, My slaves (i.e. the true believers of Islamic Monotheism) — you have no authority over them. And All-Sufficient is your Lord as a Guardian’”

[al-Israa’ 17:62-64 – interpretation of the meaning] 

Hence the Shaytaan declared his evil and his enmity towards the children of Adam, so he started to make sin attractive to them and to tempt them with haraam and evil things, and to enjoin evil and immoral actions upon them. Thus most of the people were deceived by him and they fell into those sins and haraam things: 

“And indeed Iblees (Satan) did prove true his thought about them, and they followed him, all except a group of true believers (in the Oneness of Allaah)”

[Saba’ 34:20 – interpretation of the meaning] 

Everything that happens among the sons of Adam of kufr, murder, enmity, hatred, the spread of immorality and zina, the wanton display of women’s beauty, drinking alcohol, worshipping idols and other major sins, is all the work of the Shaytaan, in order to prevent people from following the way of Allaah and to corrupt mankind and drag them to the Fire of Hell with him: 

“O you who believe! Intoxicants (all kinds of alcoholic drinks), and gambling, and Al-Ansaab (stone altars), and Al-Azlaam (arrows for seeking luck or decision) are an abomination of Shaytaan’s (Satan’s) handiwork. So avoid (strictly all) that (abomination) in order that you may be successful.

Shaytaan (Satan) wants only to excite enmity and hatred between you with intoxicants (alcoholic drinks) and gambling, and hinder you from the remembrance of Allaah and from As Salaah (the prayer). So, will you not then abstain?”

[al-Maa’idah 5:90-91 – interpretation of the meaning] 

Allaah has warned us against following the Shaytaan and walking in his footsteps, as He says (interpretation of the meaning): 

“O you who believe! Follow not the footsteps of Shaytaan (Satan). And whosoever follows the footsteps of Shaytaan (Satan), then, verily, he commands Al Fahshaa’ [i.e. to commit indecency (illegal sexual intercourse)], and Al Munkar [disbelief and polytheism (i.e. to do evil and wicked deeds; and to speak or to do what is forbidden in Islam)]

[al-Noor 24:21] 

When a person turns away from Allaah, the Shaytaan gains control over him and encourages him to commit sin and transgression: 

“See you not that We have sent the Shayaateen (devils) against the disbelievers to push them to do evil

[Maryam 19:83 – interpretation of the meaning] 

Everyone who turns away from Allaah and follows the Shaytaan is only destroying his own self and is a loser in this world and in the Hereafter: 

“And whoever takes Shaytaan (Satan) as a Wali (protector or helper) instead of Allaah, has surely, suffered a manifest loss

[al-Nisa’ 4:119 – interpretation of the meaning] 

The Shaytaan uses strange ways to tempt people; he has corrupted many of mankind and made their evil deeds attractive to them, so he is the cause of their going to Hell, what a terrible fate! 

“He [Shaytaan (Satan)] makes promises to them, and arouses in them false desires; and Shaytaan’s (Satan) promises are nothing but deceptions.

The dwelling of such (people) is Hell, and they will find no way of escape from it

[al-Nisa’ 4:120-121 – interpretation of the meaning] 

The enmity of the Shaytaan towards Adam and his descendents is ancient. Allaah caused Adam and his wife to dwell in Paradise, then the Shaytaan came to Adam and made sin attractive to him, so Adam obeyed him, thinking that he was sincere. Thus Adam disobeyed his Lord and was expelled from Paradise, then Allaah accepted his repentance. Allaah warns us against obeying the Shaytaan, as He says (interpretation of the meaning): 

“O Children of Adam! Let not Shaytaan (Satan) deceive you, as he got your parents [Adam and Hawwa’ (Eve)] out of Paradise

[al-A’raaf 7:27] 

Because the enmity of Shaytaan towards mankind is so clear and obvious, Allaah tells us to beware of him and to declare war on him and to show enmity to him, as He says (interpretation of the meaning): 

“Surely, Shaytaan (Satan) is an enemy to you, so take (treat) him as an enemy. He only invites his Hizb (followers) that they may become the dwellers of the blazing Fire

[Faatir 35:6] 

Allaah has told us to seek refuge with Allaah from the outcast Shaytaan every time we think of sinning. He says (interpretation of the meaning): 

“And if an evil whisper from Shaytaan (Satan) tries to turn you away (O Muhammad) (from doing good), then seek refuge in Allaah. Verily, He is the All Hearer, the All Knower

[Fussilat 41:36] 

On the Day of Resurrection, the Day of truth and justice, the Shaytaan will confess to his crimes and will declare before all of creation that Allaah is the One Who tells the truth and that he is a liar. He will say that there is no blame on him; rather the blame is on those who followed him. Then everyone who followed him will regret it, but at that time regret will be of no avail: 

“And Shaytaan (Satan) will say when the matter has been decided: ‘Verily, Allaah promised you a promise of truth. And I too promised you, but I betrayed you. I had no authority over you except that I called you, and you responded to me. So blame me not, but blame yourselves. I cannot help you, nor can you help me. I deny your former act in associating me (Satan) as a partner with Allaah (by obeying me in the life of the world). Verily, there is a painful torment for the Zaalimoon (polytheists and wrongdoers)’”

[Ibraaheem 14:22 – interpretation of the meaning] 

From Usool al-Deen al-Islami by Shaykh Muhammad ibn Ibraaheem al-Tuwaijri