The issue with all religions except christianity is that they have salvation by works, and they do not tell you where you're going when you die
Muhammad never claimed to know where he was going when he died, and no muslim knows, and the Quran doesn't tell you
Only the Bible tells saved believers, to know where they're going when they die:
1 John 5:13
13 These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
Muhammad never claimed to know where he was going when he died, and no muslim knows, and the Quran doesn't tell you
Only the Bible tells saved believers, to know where they're going when they die:
1 John 5:13
13 These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
How exactly is the Qur'an not clear on where believers/disbelievers go after death? It's stated dozens of times. Let alone the narrations from Prophet Muhammed pbuh.
Just one example is Surah 2, Ayat 25:
"And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. Whenever they are provided with a provision of fruit therefrom, they will say, "This is what we were provided with before." And it is given to them in likeness. And they will have therein purified spouses, and they will abide therein eternally."
Believing and doing good deeds -> Paradise
A hadith about deeds (works) alone not being the reason one will be granted Paradise:
"Aisha reported: The Messenger of Allah, peace and blessings be upon him, said, “Follow the right course, be devoted, and give glad tidings. Verily, none of you will enter Paradise by his deeds alone.” They said, “Not even you, O Messenger of Allah?” The Prophet said, “Not even myself, unless Allah grants me His mercy. Know that the most beloved deed to Allah is done regularly, even if it is small.”
Source: Ṣaḥīḥ al-Bukhārī 6464, Ṣaḥīḥ Muslim 2818