Any prophet adding to His word or taking away from it, we are not to follow.
In someways I agree, Paul warned the elders of the church in Acts 20;
28 ¶ Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood.
29 For I know this, that after my departing shall grievous wolves enter in among you, not sparing the flock.
30
Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them.
He was prophesying of the many councils which would arise and from which the Christian creeds would emerge. The Apostles Creed which was written before 390 AD was simple
"I believe in God, the Father Almighty, the Creator of heaven and earth, and in Jesus Christ, His only Son, our Lord....I believe in the Holy Spirit..."
1250 years later the Westminster Confession of 1640 is adding tremendously to that simple confession.
"There is but one only living and true God, who is infinite in being and perfection, a most pure spirit, invisible, without body, parts, or passions, immutable, immense, eternal, incomprehensible, almighty, most wise, most holy, most free, most absolute.... In the unity of the Godhead there be three Persons of one substance, power, and eternity: God the Father, God the Son, and God the Holy Ghost."
I have to say how surprised I was as I began to study with an Evangelical lady many year ago at how much Christianity had taken away from the teachings of the Bible. She told me there was no priesthood and baptism was not necessary yet I read
" Jesus Christ ....hath made us kings and priests unto God and his Father" Rev 1
"He that believeth and is baptized shall be saved; but he that believeth not shall be damned" Mark 16:16
*However on the other hand I disagree.
Peter taught;
19 We have also a more sure word of prophecy; where unto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts:
20 Knowing this first, that no prophecy of the scripture is of any private interpretation.
Peter is saying they have the gift of prophecy but first check it with the scriptures, you can't start making things up, this I understand. But he didn't say there will be no more prophecy.
But Paul taught in 1Thess 5
19 Quench not the Spirit.
20 Despise not prophesyings.
Rom 12 talks of prophecy with the proportion of faith we have
5 So we, being many, are one body in Christ, and every one members one of another.
6 Having then gifts differing according to the grace that is given to us, whether prophecy, let us prophesy according to the proportion of faith;......
Paul also taught in 1 Cor 12
3 Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.
4 Now there are diversities of gifts, but the same Spirit.
5 And there are differences of administrations, but the same Lord.
6 And there are diversities of operations, but it is the same God which worketh all in all.
7 But the manifestation of the Spirit is given to every man to profit withal.
8 For to one is given by the Spirit the word of wisdom; to another the word of knowledge by the same Spirit;
9 To another faith by the same Spirit; to another the gifts of healing by the same Spirit;
10
To another the working of miracles; to another prophecy; to another discerning of spirits; to another divers kinds of tongues; to another the interpretation of tongues:
11 But all these worketh that one and the selfsame Spirit, dividing to every man severally as he will.
So if any man or group has 'the Spirit' they should have these gifts of the Spirit.
However in the very next chapter he gives a prophecy of the coming future.
8 Charity never faileth: but whether there be
prophecies, they shall fail; whether there be
tongues, they shall cease; whether there be
knowledge, it shall vanish away.
Prophecies fail? knowledge vanish away? the word being used there is
katargeō, Strongs says it means
"to cause to cease". Why?
Paul goes on
9 For we know in part, and we prophesy in part.
He doesn't know why.
10 But when that which is perfect is come, then that which is in part shall be done away.
11 When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things. (I'm going to stop questioning and asking why and just accept it as the Lord's will)
12 For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known.
Some day that which is perfect/ Jesus will come then all that is only known in part will be done away and I will know all things.
After Joseph Smith first vision he had this experience;
21 Some few days after I had this vision, I happened to be in company with one of the Methodist preachers, who was very active in the before mentioned religious excitement; and, conversing with him on the subject of religion, I took occasion to give him an account of the vision which I had had. I was greatly surprised at his behavior; he treated my communication not only lightly, but with great contempt, saying it was all of the devil, that there were no such things as visions or revelations in these days;
that all such things had ceased with the apostles, and that there would never be any more of them.
That preacher nailed it, the workings of the Spirit had 'ceased' the spiritual gifts were gone. Why again? Well we know now the priesthood was gone so no one could have the gift of the Holy Ghost given to them by the laying on of hands. No one in Evangelical land even believes there is such a thing as a priesthood or this special gift of the Holy Ghost.
Now that is not saying that the Holy Ghost didn't testify or prick the true believer in his heart to know Christ nor am I saying that men didn't have faith to pray for a healing.
But it's the "spiritual gifts" of knowledge, prophecy and the gift of tongues ceases.
With Joseph Smith's first vision "the dispensation of the fulness of times" has begun, the gifts of the Spirit have come to the earth again. Prophecy and knowledge of the true gospel have been returned.
Mormonism isn't something new but the original Gospel taught by our Savior in the New Testament.