He has sent down upon His Messenger, and the Book that He sent down before. Whoever disbelieves in Allah, His angels, His Books, His messengers, and the Last Day has indeed strayed far away.” [al-Nisā: 136]

Then our gracious Lord informed us that the sign of the sincerity of anyone who claims to love Allah Most High is that he loves His Messenger Muhammad—may Allah bless him and grant him peace—and follows him. Otherwise, his love for Allah—glorious and mighty—cannot be genuine. Allah—glorious and mighty—said:

“Say: If your fathers, your sons, your brothers, your spouses, your kindred, the wealth you have acquired, the trade whose decline you fear, and the dwellings in which you delight are dearer to you than Allah, His Messenger, and striving in His path, then wait until Allah brings about His command. Allah does not guide the defiantly disobedient people.” [al-Tawbah: 24]

He—glorious and mighty—also said:

“Say: If you love Allah, then follow me; Allah will love you and forgive you your sins. Allah is All-Forgiving, Most Merciful.” [Āl Imrān: 31]

Thus Allah—glorious and mighty—made loving and following His Messenger a sign and proof of the genuineness of their love for Him, together with their following His Messenger in what he brought, commanded, and forbade. He—glorious and mighty—then declared that whoever disbelieves in His Messenger is like one who disbelieves in Allah, and whoever rejects His Messenger as false has thereby rejected Allah—mighty and majestic—as false.