Say Seal of the Prophets and don't say Seal of the Messengers
Belief in the messengers is the fourth pillar of faith. A person’s faith is not valid without them. The evidence from the Shari’ah is abundant to confirm this. Allah the Almighty has commanded belief in them and linked that to belief in Him, saying: {So believe in Allah and His messengers} (An-Nisa’: 171). Belief in them came in the fourth rank in the prophetic definition of faith, as in the hadith of Gabriel: (To believe in Allah, His angels, His books, and His messengers…) narrated by Muslim. Allah the Almighty linked disbelief in the messengers with disbelief in Him, saying: {And whoever disbelieves in Allah, His angels, His books, His messengers, and the Last Day has certainly gone far astray} (An-Nisa’: 136). These verses demonstrate the importance of belief in the messengers and its status in the religion of Allah the Almighty.
When you say, my Muslim brother, that our Master Muhammad, may God bless him and grant him peace, is the Seal of the Messengers and not just the Seal of the Prophets, as stated in the Qur’an and Sunnah, then by saying that our Master Muhammad is the Seal of the Messengers you deny all of the Messengers of God Almighty, including the Angel of Death and other Messengers who have always been among us since the death of our Master Muhammad, may God bless him and grant him peace, until now, in every time and place.
God Almighty said: {The Messenger has believed in what was revealed to him from his Lord, and [so have] the believers. All of them have believed in God and His angels and His books and His messengers. We make no distinction between any of His messengers.} (Al-Baqarah: 285)
When you say that our master Muhammad is the seal of the messengers, what exactly do you mean?
If you mean that our master Muhammad is the seal of the messengers from among mankind only, then say that and do not generalize that our master Muhammad is the seal of all the messengers, so that you do not fall within the scope of the verses that I mentioned previously.
If you say that our master Muhammad is the only seal of the messengers from among mankind, then give me evidence for that from the Qur’an and Sunnah and do not tell me that since our master Muhammad is the seal of the prophets then he is the seal of the messengers because I will say to you, do you know the difference between a prophet and a messenger?
Know the difference first between a prophet and a messenger in the first two chapters of the book “The Awaited Messages” via this link before answering these questions. Do not tell me that this is what we found our fathers doing and that you are contradicting the consensus of scholars and that you are denying something that is known from the religion by necessity.