Is the message brought by our Prophet Muhammad, may Allah's prayers and peace be upon him, the religion of Islam, and what is the meaning of "he delivered the message and advised the Ummah"?

If a person says that Muhammad, peace and blessings be upon him, has delivered the message, its meaning is the religion of Islam, which aims to purify and cleanse souls through the knowledge and worship of God, and to strengthen human bonds on the foundations of love, mercy, brotherhood, equality, and justice, so that humanity may be happy in this world and the hereafter, in fulfillment of His Almighty saying: "It is He who sent among the unlettered a messenger from themselves, reciting to them His verses and purifying them and teaching them the Book and wisdom - although they were before in clear error."