All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Islam urges unity and harmony and forbids division and disagreement, and labels them as signs of insincere worship. Allaah The Almighty Says (what means): {And do not be of those who associate others with Allaah. [Or] of those who have divided their religion and become sects.}[Quran 30:31-32]
There are several verses and Hadeeths denouncing division and disagreement while urging unity. Therefore, Muslims should avoid any sign of disagreement, even about secondary or minor issues.
Congregational prayers are the most important sign of Muslim unity; Muslims stand in one row at the same time behind one Imaam, facing one direction, worshipping one Lord, embracing one religion and adopting one approach. Disagreement about performing prayer in the same country is a sign of disunity. The Muslims there must unite around one ruling concerning the time of prayer.
And Allaah Knows best.