Ok, I am studying what the church has taught about Gethsemane, and it is pretty interesting to me, so I thought I would post it here and also ask for a little help.
You see, I can’t find any reference to Joseph Smith or Brigham Young ever mentioning Gethsemane in any sermon. (I am not including any statement in the current scriptures in this study.) Sure, they talk about the atonement in the abstract, but when it comes to the event in gethsemane, they seem to be silent.
Further, the only quote from John Taylor (He doesn’t even mention it in Mediation and Atonement! updated:I stand corrected, thanks Justin. )is the following:
It was necessary that he should have a body like ours, and be made subject to all the weaknesses of the flesh,-that the Devil should be let loose upon him, and that he should be tried like other men. Then, again, in Gethsemane, he was left alone; and so great was the struggle, that we are told he sweat, as it were, great drops of blood. In the great day when he was about to sacrifice his life, he said, “My God, my God, why hast thou forsaken me?” He has passed through all this, and when he sees you passing through these trials and afflictions, he knows how to feel towards you-how to sympathise with you. It was necessary that he should pass this fiery ordeal; for such is the position of things, and such the decrees of the Allwise Creator.
-John Taylor, Journal of Discourses 7:194 
I can’t find a single reference from Wilford Woodford on Gethsemane, but from Lorenzo Snow, I have the following three:
It was difficult for Jesus to accomplish the Atonement. Jesus, the Son of God, was sent into the world to make it possible for you and me to receive these extraordinary blessings. He had to make a great sacrifice. It required all the power that He had and all the faith that He could summon for Him to accomplish that which the Father required of Him. Had He fallen in the moment of temptation, what do you suppose would have become of us? Doubtless at some future period the plan would have been carried out by another person. But He did not fail, though the trial was so severe that He sweat great drops of blood. When He knelt there in the Garden of Gethsemane, what agony He must have experienced in contemplating His sufferings on the cross! His feelings must have been inexpressible. He tells us Himself, as you will find recorded in section 19 of the book of Doctrine and Covenants, that His suffering was so great that it caused even Him “to tremble because of pain, and to bleed at every pore, and to suffer both body and spiritâ€”and would that [He] might not drink the bitter cup, and shrink.” But He had in His heart continually to say, “Father, not my will, but Thine be done.” It was a dark hour for Him; and every man and woman who serves the Lord, no matter how faithful they may be, have their dark hours; but if they have lived faithfully, light will burst upon them and relief will be furnished. (18 May 1899, MS, 61:531.)
Do not compromise to avoid suffering. Some of our brethren have queried whether hereafter they could feel themselves worthy of full fellowship with prophets and Saints of old, who endured trials and persecutions; and with Saints of our own times who suffered in Kirtland, in Missouri, and Illinois. The brethren referred to have expressed regrets that they had not been associated in those scenes of suffering. If any of these are present, I will say, for the consolation of such, you have to wait but a short time and you will have similar opportunities, to your heart’s content. You and I cannot be made perfect except through suffering; Jesus could not. In His prayer and agony in the Garden of Gethsemane, He foreshadowed the purifying process necessary in the lives of those whose ambition prompts them to secure the glory of a celestial kingdom. None should try to escape by resorting to any compromising measures. “All who journey soon or late, Must come within the garden gate, And kneel alone in darkness there, And battle hard, yet not despair.” (10 January 1886, JD, 26:367.)
The Lord will help us overcome trials. From the time of our receiving the gospel to the present, the Lord has from time to time given us trials and afflictions if we may so call them; and sometimes these trials have been of that nature that we have found it very difficult to receive them without murmur and complaint. Yet at such times the Lord blessed us and gave us sufficient of His Spirit to enable us to overcome the temptations and endure the trials. In going through these trials and troubles we are doing no more than did the captain of our salvation. We are told by the Apostle Paul that He was made perfect through sufferings. And even He, the Son of God, at times found it very difficult. For example, in the Garden of Gethsemane, when the time approached that He was to pass through the severest affliction that any mortal ever did pass through, He undoubtedly had seen persons nailed to the cross, because that method of execution was common at that time, and He understood the torture that such persons experienced for hours. He went by Himself in the garden and prayed to His Father, if it were possible, that that cup might pass from Him; and His feelings were such that He sweat great drops of blood, and in His agony there was an angel sent to give Him comfort and strength. Even the Son of God required miraculous help under those extraordinary circumstances. So we have needed it at times, and so we may in the future. (4 November 1893, DW, 47:609.)
After this, I have no reference to Gethsemane from Joseph F. Smith, Heber J. Grant, or George Albert Smith. David O. McKay has numerous references, as do most Presidents post “Jesus the Christ”
So what’s the oldest reference to Gethsemane in post-1830 Church History that you know of? Am I just laccking the right sources or the right searches? Ought we assume that Gethsemane was not commonly understood as the place of atonement before Talmage brought it to light in his book?
This is one of only three references to Gethsemane in the whole Journal of Discourses, the other two being one of the Lorenzo Snow Quotes above and this from Elder Moses Thatcher:
“Public opinion followed Jesus Christ into the garden of Gethsemane when, alone and unwatched by His Apostles, He prayed to the Father for strength to endure suffering which caused drops of blood to ooze from every pore of his agonized body” JD 23:196