Founder of the Church of Jesus Christ of Latter Day Saints (Mormonism), Joseph Smith of America, says –

"I was once praying very earnestly to know the time of the coming of the Son of Man, when I heard a voice repeat the following: Joseph, my son, if thou livest until thou art eighty-five years old, thou shalt see the face of the Son of Man; therefore let this suffice, and trouble me no more on this matter." (Doctrine & Covenants 130:14-15, emphasis mine).

Again, Joseph Smith also declares –

February 14: Joseph Smith, the founder of the Mormon church, calls a meeting of his church leaders 'because God has commanded it' and announces that Jesus will return within 56 years ('History of the Church' 2:182, emphasis mine). (See: 1891).

Joseph Smith dies without seeing the Lord's Return or his 85th birthday (See 1832).

February 14: Joseph Smith, the founder of the Mormon church, 1835 prediction that Jesus would return within 56 years now fails!

"And if you say in your heart, 'How may we know the word that the LORD has not spoken?' –
when a prophet speaks in the name of the LORD, if the word does not come to pass or come true,
that is a word that the LORD has not spoken; the prophet has spoken it presumptuously.
You need not be afraid of him." (i.e. He has no authority).

The description of the New Jerusalem in Revelation 21:14 often used by Mormons as material for deceit by asking –
'There are so many churches, so how do we know which is the right one? Let's turn to the Bible [and Revelation 21 is then read]. So, the true church is identified by being based on the leadership of twelve apostles!
The only church today which is led by twelve apostles is that based in Salt Lake City, Utah, the Church of Jesus Christ of Latter Day Sanits.'

the Bible says that it is the "names" of the Twelve Apostles which are written in the foundation of the New Jerusalem, not their offices, titles, or positions, that could ever be filled/inherited by others.

foundation-symbolism in the Bible is a reference to unique individuals who became the historical foundation of Christianity on the Day of Pentecost when the Holy Spirit was given.

That is why the qualification for the replacement of Judas Iscariot among the Twelve was restricted to that those persons who had to have been an eye-witnesses of the human ministry of The Lord Jesus – from the time He was baptised by John until He was taken up to God at His acension (Acts 1:21-22). And so out of the many disciples of Jesus there were only two that qualified!

Not one Mormon has ever qualified to be one of the Twelve, and never can!