Although jihad is a collective obligation, its command is initially addressed to all believers. They must therefore all believe it to be obligatory and resolve to undertake it if it becomes individually binding upon them. Hence the Prophet, may Allah bless him and grant him peace, said:
“Whoever dies without having fought in a military campaign and without having contemplated doing so dies with a trait of hypocrisy.”
Reported by Muslim. He thus stated that anyone who has not entertained the intention of doing so has a trait of hypocrisy. Moreover, jihad encompasses various kinds, and some kind of it must necessarily be obligatory upon every believer.
The same applies to His words:
“The believers are only those whose hearts tremble when Allah is mentioned, whose faith increases when His verses are recited to them, and who put their trust in their Lord; those who establish prayer and spend from what We have provided for them. It is they who are truly believers.”
All of this is obligatory. Reliance upon Allah is indeed among the greatest obligations, just as sincerity to Allah is obligatory, and love for Allah and His Messenger is obligatory.
Allah has commanded reliance upon Him in numerous verses, with greater emphasis than His command to perform ablution and to bathe after sexual impurity. He has also forbidden reliance upon anyone other than Allah. The Most High says:
“So worship Him and put your trust in Him.”
And the Most High says:
“Allah—there is no deity worthy of worship except Him. And in Allah let the believers put their trust.”
And the Most High says:
“If Allah helps you, none can overcome you; but if He forsakes you, who can help you after Him? And in Allah let the believers put their trust.”
And the Most High says:
“Moses said, ‘My people, if you have believed in Allah, then put your trust in Him, if you are Muslims.’”
As for His words:
“Those whose hearts tremble when Allah is mentioned, and whose faith increases when His verses are recited to them,”
we say: Among the states and actions of the heart are those that necessarily accompany faith and are firmly established within the heart, such that, if a person is a believer, they necessarily follow without his intending them or deliberately bringing them about