It is hypocrisy to join a movement because of its worldly success

When the Prophet emigrated to Madinah, Abdullah ibn Ubayy and his followers put all kinds of obstacles in the Prophet’s path, doing all they could to sabotage his mission. Then came the Battle of Badr, when the great leaders of the Quraysh were slain. “There is no stopping Islam now,” agreed Abdullah ibn Ubayy and his companions. They then put up a facade of entering Islam, but, insincere in their path, they soon took to plotting against Islam.