Dought & clear, - Is the will of Allaah the reason why people go astray?.

When a person goes astray and deviates, does that happen by the will
of Allaah or does Allaah not decree that?
Praise be to Allaah.
Shaykh al-Shanqeeti (may Allaah have mercy on him) said:
Allaah says (interpretation of the meaning):
"He whom Allaah guides, he is the rightly-guided; but he whom He sends
astray, for him you will find no Wali (guiding friend) to lead him (to
the Right Path)"[al-Kahf 18:17]
In this aayah, Allaah explains that guidance and misguidance are in
His hand alone; whomsoever He guides none can lead astray, and
whomsoever He sends astray, none can guide. This meaning is also
expressed in many other aayahs, such as the following (interpretation
of the meaning):
"He whom Allaah guides, he is the rightly-guided; but he whom He sends
astray, for him you will find no Wali (guiding friend) to lead him (to
the Right Path)."[al-Israa' 17:97]
"Whomsoever Allaah guides, he is the guided one, and whomsoever He
sends astray, — then those! they are the losers"[al-A'raaf 7:178]
"Verily, you (O Muhammad) guide not whom you like, but Allaah guides
whom He wills"[al-Qasas 28:56]
"And whomsoever Allaah wants to put in Al-Fitnah (error, because of
his rejecting of Faith), you can do nothing for him against Allaah"
[al-Maa'idah 5:41]
"If you (O Muhammad) covet for their guidance, then verily, Allaah
guides not those whom He makes to go astray (or none can guide him
whom Allaah sends astray). And they will have no helpers"
[al-Nahl 16:37]
"And whomsoever Allaah wills to guide, He opens his breast to Islam;
and whomsoever He wills to send astray, He makes his breast closed and
constricted, as if he is climbing up to the sky"
[al-An'aam 6:125]
And there are very many similar aayahs.
From these and similar aayahs in the Qur'aan it may be understood that
the view of the Qadariyyah, who say that man is independent in his
actions, whether good or bad, and that does not happen by the will of
Allaah but rather by the will of the person, is false. Glorified and
exalted be Allaah far above anything happening in His dominion that
does not happen by His will.
Adwaa' al-Bayaan, 4/44.