Just as loyalty and sincere devotion to Allah, brotherhood and
solidarity are the important attributes of believers. The Qur’an
tells that all believers are brothers; they are the people
sharing the same feelings who strive for the same end, adhere to
the same book and struggle to reach the same goal. Consequently,
solidarity becomes the natural feature of a community made up of
believers. Allah describes this attachment of believers in the
following verse: Truly Allah loves those who fight in His Cause
in battle array, as if they were a solid cemented structure.
(As-Saff, 4) As related in the verse above, fighting in the
cause of Allah is a command of Allah. And hold fast, all
together, by the rope which Allah (stretches out for you), and
be not divided among yourselves; and remember with gratitude
Allah's favor on you; for you were enemies and He joined your
hearts in love, so that by His Grace, you became brethren; and
you were on the brink of the pit of Fire, and He saved you from
it. Thus do Allah make H