According to John 16, this is why Jesus sent the Holy Spirit upon believers, the Body of Christ:
"…12"I have many more things to say to you, but you cannot bear them now. 13"But when He, the Spirit of truth, comes, He will guide you into all the truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose to you what is to come. 14"He will glorify Me, for He will take of Mine and will disclose it to you.… John 16:
Okay, Mormons who come here pretending that Jesus' Church became apostate, that it lost all authority, take a good look at these words spoken by God Incarnate, Jesus Christ, and tell us that Jesus' words failed (per your false prophet, Joe Smith):
1. Jesus had more things to teach the Church which they could not bear at the time. What things were these? Well about things to come (eschatology); about the glorification of the Lord Jesus (theology), as expounded in the creedal statements forumulated by the Body of Christ in Councils to protect against the inroads of false brethren and heretics who were diminishing Christ and His Work. The Gnostics and Arians being the chief enemies of Christ confronted by early Christians. These heretics still raise their ugly heads in cultic systems such as Mormonism and the Jehovah's Witnesses.
2. The Holy Spirit was poured out upon the Church, to gift the Church with the charismata, and to lead Christians into "all the truth." This outpouring led all true Christians to believe the CORE DOCTRINES of the Christian faith. These doctrines include (but are not necessarily limited to):
1. The Holy Trinity: Father, Son and Holy Spirit, three Persons in on Triune God (a Triune Center of Being)
2. Jesus Christ is God in the flesh, and is both Fully God and Fully Man by NATURE
3. Jesus Christ came to earth and was born of the Blessed Virgin Mary WITHOUT the "aid" of men
4. Jesus Christ founded His Church, was Crucified, Died, and Buried
5. Jesus Christ rose from death in His SAME physical body on the Third Day and appeared to many witnesses
6. Jesus Christ ascended to heaven, and sits on the "right hand" (meaning place of authority) of the Father
7. Jesus Christ poured out the Holy Spirit upon the Church to guide His Church into all truth and to preserve the Body of Christ until He comes again
8. Salvation is through faith in the finished work of Jesus Christ upon the Cross as an Atonement for sin.
9. The written Word of God is found in the bible and contains all things necessary for salvation and doctrine.
10. Jesus Christ has commanded us to go out into all the world and baptize those who believe in the Name of the Blessed Trinity
11. Jesus Christ has commanded us to observe the Lord's Supper in memory of His death until He comes again.
12. Jesus Christ will return to judge both the Living and the Dead.
13: There will be a bodily resurrection of men - some to Life Everlasting, and some to ****ation.
While different denominations may have their own unique takes on some of the above (sacramental action for instance), and there are different traditions of ritual and liturgy found throughout the Body of Christ, Christians have been led to these core doctrines by the Holy Spirit poured out upon the Church. These doctrines of stood for over 2,000 years and and are taught throughout the Christian world faithfully by those who have been ordained to Christian ministry.
Mormons have lied to us by telling us that Jesus' Church failed, that it has no authority, that Jesus had to depend on an occultist of the 19th century to restore His Church - an occultist who basically trashed all of the historic doctrines of Christianity in favor of vulgar variations such as polytheism, men becoming gods and goddesses, the highest heaven dependent upon marriage, polygamy as necessary for exaltation, and all kinds of other bizarre teachings that completely deviate from the body of faith and doctrine the Body of Christ was taught by the Holy Spirit given to us by Christ.
It is a blasphemy against the Holy Spirit to deny Jesus' promise that the Hol Spirit would lead the Church into all truth, and to claim He could not do it - and that Joseph Smith needed to replace the Spirit of the True and Living God as the source of truth! There is some speculation that Smith insinuated that he was the Holy Ghost incarnate. Fortunately, Smith was disposed of before fully developing this blasphemous lie. Joseph Smith was an evil man, and his lifestyle identifies him as such. Do not trust in Smith's words, but believe that the Holy Spirit was sent to Jesus' Church and is still here today, endowing believers with discernment and all the gifts necessary to live as the Body of Christ in the world, but not of it.