What does "introducing the principles of Islam" include?

The Prophet, peace and blessings be upon him, defined Islam through his verbal and practical Sunnah, encompassing its pillars and foundations. He would first invite to bearing witness that there is no god but Allah and that Muhammad is the Messenger of Allah, then to establishing prayer, giving zakat, fasting Ramadan, and performing Hajj to the House, followed by the rest of the duties, Sunnahs, and manners. The Prophet, peace and blessings be upon him, commanded the delegation of Abd al-Qays to worship Allah alone, establish prayer, give zakat, and fast Ramadan. He also advised Mu'adh ibn Jabal to first invite to monotheism, then to prayer, then to zakat. These hadiths affirm the necessity of focusing on the principles and pillars first.