I will use an anti web site for my source, look for it at the bottom. In the quote by Joseph F. Smith, notice him saying that blood atonement for ones' sins can be done as far as it is in their power to do so. They DO NOT have that power, only Christ has that power. The doctrine of blood atonement was taught by Joseph, as indicated by Joseph Fielding Smith Jr. (10th prophet): "Just a word or two now, on the subject of blood atonement. What is that doctrine? Unadulterated, if you please, laying aside the pernicious insinuations and lying charges that have so often been made, it is simply this: Through the atonement of Christ all mankind may be saved, by obedience to the laws and ordinances of the gospel. Salvation is twofold: General -- that which comes to all men irrespective of a belief (in this life) in Christ -- and, Individual -- that which man merits through his own acts through life and by obedience to the laws and ordinances of the gospel. "But man may commit certain grievous sins -- according to his light and knowledge -- that will place him beyond the reach of the atoning blood of Christ. If then he would be saved he must make sacrifice of his own life to atone --so far as in his power lies-- for that sin, for the blood of Christ alone under certain circumstances will not avail. "Do you believe this doctrine? If not, then I do say you do not believe in the true doctrine of the atonement of Christ. This is the doctrine you are pleased to call the "blood atonement of Brighamism." This is the doctrine of Christ our Redeemer, who died for us. This is the doctrine of Joseph Smith, and I accept it." (McConkie, Bruce R., ed. Doctrines of Salvation, Vol. 1, pp. 133 - 135, Salt Lake City: Bookcraft, 1954-1955) Notice below, that BY says IF men could atone for their own sins, they would. Just like men would have the mountains cover them to hide their sins from the Messiah when he comes. It is rhetorical, because you CANNOT hide your sins from the Lord. Man cannot atone for their sins, hence they are unforgiveable. Brigham Young clearly explained the doctrine of blood atonement in a sermon given on September 21, 1856: "There are sins that men commit for which they cannot receive forgiveness in this world, or in that which is to come, and if they had their eyes open to see their true condition, they would be perfectly willing to have their blood spilt upon the ground, that the smoke thereof might ascend to heaven as an offering for their sins; and the smoking incense would atone for their sins, whereas, if such is not the case, they will stick to them and remain upon them in the spirit world. "I know, when you hear my brethren telling about cutting people off from the earth, that you consider it is strong doctrine; but it is to save them, not to destroy them… "And further more, I know that there are transgressors, who, if they knew themselves, and the only condition upon which they can obtain forgiveness, would beg of their brethren to shed their blood, that the smoke thereof might ascend to God as an offering to appease the wrath that is kindled against them, and that the law might have its course. I will say further; "I have had men come to me and offer their lives to atone for their sins. "It is true that the blood of the Son of God was shed for sins through the fall and those committed by men, yet men can commit sins which it can never remit.... There are sins that can be atoned for by an offering upon an altar, as in ancient days; and there are sins that the blood of a lamb, or a calf, or of turtle dove, cannot remit, but they must be atoned for by the blood of the man." (Brigham Young, Journal of Discourses, Vol. 4, pp. 53-54); also published in Deseret News, 1856, p. 235) http://trialsofascension.net/mormon/blood.html
