How should a Muslim deal with the sectarian disputes prevalent among parties and groups?

A Muslim is obligated to adhere to the truth derived from the Book of Allah and the Sunnah of His Messenger, peace and blessings be upon him, and to show loyalty to and animosity towards everything that conforms to or contradicts that. The religion of Allah is one: it is the worship of Him alone and the following of His Messenger Muhammad, peace and blessings be upon him. Therefore, a Muslim must obey Allah and follow His Sharia with sincerity to Him alone. Every school of thought or party that deviates from this must be avoided and disavowed, while inviting its adherents to the truth with wisdom and gentleness.