Al-Ḥāfiẓ Ibn Rajab (d. 795 AH) said: “In the ḥadīth of Muʿādh ibn Jabal [raḍī Allāhu ʿanhu], [the Prophet (ﷺ)] said that at the head of this matter is Islām. It is supported by ṣalāh. Jihād [struggling in the way of Allāh] is the apex of the climb. That is, the highest and most lofty position in it [is to struggle in the way of Allāh]. Considering this, jihād is not mentioned as one of [Islam’s] supports or pillars upon which it is built. There are two reasons for this:

The first is that jihād is farḍ kifāyah [obligatory on the community as a whole] according to the consensus of the scholars. It is not farḍ ʿayn [obligatory on each individual] which differentiates it from the rest of the pillars of Islām.

The second reason is that jihād will not continue until the end of time. Rather, when ʿĪsā (ʿalayhi al-salām) returns there will be no religion save for the religion of Islām. At this point, war will cease and jihād will become obsolete. This is different from the pillars of Islām as they will remain obligatory on every muʾmin until the command of Allāh is given [i.e. for the Day of Judgement to begin]. And Allāh the Exalted knows best.”  

Source: Jamiʿ al-ʿUlūm wa-al-Ḥikam: 155
Translated by: Riyāḍ al-Kanadī