Doesn’t every new prophet lead to another split in Islam?

No. A reformer subordinate to the Holy Prophet Muhammad (saw) comes only when the community is already divided. He does not come to split it but to bring the divided together again.

At first the concern sounds reasonable. If some accept a prophet and others do not, a new group seems to appear. But the question overlooks the order of events. Such a reformer does not come to a united community. He comes at a time when Muslims have already broken into many groups.

This division has deep causes. It is often about prestige, power and the number of followers, less about truth and good conduct. Where inner integrity decays, the name of religion alone is no help. People cannot heal such division by their own strength.

That is why a calling from God is needed. Whoever comes in God’s name is rejected and opposed, and yet his cause grows from weakness to strength. The verse above describes this law. The opponents may be more numerous, but the ground they stand on keeps shrinking, while the ground of truth keeps growing. In this way a real unity comes about, one that is not imposed from above.

There is another important point. Most other Muslims are also waiting for a Mahdi sent by God and for the return of the Messiah. So the question about a split would apply to their own expectation as well. What matters is whether the one who comes can support his claim from the Holy Qur’an and from the prophecies of the Holy Prophet (saw).