It really isn't. It is a matter of assent to or dissent from the historically-rooted, apostolic preaching of Christ, Who was and always will be God, Who was born of the Theotokos (the Virgin Mary), lived, preached, and at the appointed time of His own will was crucified and died upon the cross, and three days later rose from the dead, and by defeating death by His glorious and mysterious resurrection, has given us hope in the resurrection that we will be raised, to judgment and (God willing) ever-lasting life.
It is an assent from the Nicene Council that moved Christianity in another direction.
But we do believe most of what you say in this paragraph. Just like most of Christianity believes in most of what you say in this paragraph.
Mormonism disagrees with several major theological statements that form the bedrock of Christian belief (namely, the Holy Trinity), so to the extent that you will probably say or think "we believe all those things, too!", we have to ask and find out exactly
Who you believe them about. That the Mormon Jesus and the Christian Jesus are not the same is admitted by your own leaders in their speeches and writings (I believe it was in one of
Gordon B. Hinckley's interviews where he said as much about "the traditional Christ" of Christians, that this is
not the Christ of the Christians), so there's no use in denying it -- or if you do, you should stop being Mormon immediately.
There is no doubt we believe different things about God and Jesus, but the whole Christian world is a mosaic of different beliefs about God and Jesus.
I suspect you are not Protestant or Catholic because there are differences in the things they believe in and the things you believe in. So no surprise there.
That is wrong. He told us Who and what He is many times ("I and the Father are one", "I lay it down and take it up again; no one takes it from me", etc.), and the Holy Spirit guided His apostles, our holy fathers in the faith, to all truth -- not just some. To claim that there is more that we are to know is both gnosticism and a slap in the face to every Christian who ever lived, including those same apostles who personally knew Jesus Christ, and to St. Paul to whom He appeared.
Again, there is no doubt we believe differently about God and Jesus. But our holy apostles did receive all the truth, but were unable to give us all the truth because of the faithlessness of the first century church. Paul, the most quoted holy apostle, says to the Corinthians that he was not able to give them the meat of the gospel, because they would not receive it. (1 Corinthians 3:2)
So no, all truth was received, but all truth was not given. IOW if Paul had given them the whole truth, they may have killed him. As it is, he tells us towards the end of his mission that all Asia had turned away from him. (2 Timothy 1:15).
(1 Corinthians 15:12) tells us why Paul could not give the whole truth, and why all Asia had turned away from him. Some were now even questioning if there had been a resurrection.
So no, it is not a slap in the face, it is the truth that there is much more to the gospel of Jesus Christ that only since the restoration of the Church of Jesus Christ, the Lord has filled in many questions that the bible is not real clear about, and especially the "meat" of the gospel that the first century Christians were not willing to receive, because they were having big problems just living the "milk" of the gospel of Jesus Christ.
No, time won't tell. It's already been told. We've already been told to reject another gospel (another teaching); it's just that JS didn't listen, so you don't either.
Yes time will still tell, since the bible does not contain the "meat" of the gospel, then more needs to be given, much more. And it has, and time will tell whether the gospel of Jesus Christ will be received by the world in our day. I believe in the near future, things are going to happen that will be very interesting to the world of Christianity, that will change many peoples lives, as they learn more of the truth.
You follow JS and his conception of Jesus, which is incredibly heretical to every Christian who does not believe that God hit the reset button on belief in Him in 1820 or whatever. And that's basically everybody who isn't a restorationist (i.e., all Christians).
God hit the reset button in the 1500's, but it did not take. He had to wait until the 1800's before a free nation was established in the USA and the truth could be brought forth without being smashed by the state established religions. This time it took and will roll forth as a stone cut out without hands and will smite the image and break it to pieces and continue to roll forth to become a great mountain, and fill the whole earth. You are seeing this being fulfilled in our day.