Why do we invite people to Islam, even though those who have not received the message are excused, while those who have received it and do not believe are considered disbelievers?

We invite to Islam in compliance with Allah's command to convey the religion. The Prophet, peace and blessings be upon him, was sent as a guide, a bringer of good tidings, and a warner, and Muslims inherited his call. Allah has commanded us to invite to Him, and has made the criterion of goodness in the Ummah to be enjoining good and forbidding evil. There are great rewards in inviting to Allah, and whoever invites to guidance will have the reward of those who follow him. We seek to explain the merits of Islam and the proofs of the Prophet's truthfulness to disbelievers who have received the call, so that they may perhaps follow the truth and be saved from eternal Hellfire. As for those who have not received the call, they will be tested on the Day of Judgment. Inviting to Islam benefits those invited and saves them from misguidance; leaving them without invitation is not a reason for their salvation.