Allah (SWT) says in the Noble Qur'an: "And hold fast, all
together,
by the rope which Allah (stretches out for you), and be not divided
among yourselves." (3:103)
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Allah (SWT) says in the Noble Qur'an: "The believers are but a single brotherhood. Make peace and reconciliation between your two (contending) brothers and fear Allah so that you may receive mercy." (49-10)
Allah (SWT) says in the Noble Qur'an: "As for those who divide
their religion and break up into sects, you have no part in them in the least:
their affair is with Allah. He will in the end, tell them the truth of all that
they did." (6-159)