Is an individual responsible only for himself, or for his brethren who witness forbidden things and do not heed his advice?

The Sharia obligates a Muslim to enjoin good and forbid evil according to their ability. Whoever sees an evil, let them change it with their hand; if they are unable, then with their tongue; and if they are unable, then with their heart, for that is the weakest of faith. If a Muslim acts according to their ability, the misguidance of others will not harm them. This does not mean that it is permissible to abandon enjoining good and forbidding evil, as guidance is not achieved without them. If a Muslim is unable to denounce with their hand and tongue and denounces it with their heart, the misguidance of others will not harm them. It is advisable to consistently offer sincere advice with wisdom and gentleness, to present beneficial materials, to seek assistance from the righteous, to cooperate in acts of obedience, and to listen to admonitions, while persistently supplicating for their guidance.