Around the year 1510, a delegation of Christians from Sudan, which had been recently overrun by Muslim conquest, went to the Christian Ethiopian court and begged the emperor to send them bishops and priests. The Christians remaining in Sudan needed clergy to lead worship, administer the sacraments, and teach the people. But the emperor refused, sending them away empty-handed.
With no Christian worship, within 100 years Christianity in Sudan became extinct and forgotten until the twentieth century.
That historical moment is a useful example for Christians today.