God does not condone human sacrifice. The sacrifice of the Only Begotten was a divine sacrifice not a human one. The individual offered had to have the qualities of Godhood in order for it to be infinite and eternal. Now there is not any man that can sacrifice his own blood which will atone for the sins of another (v. 11). Tad Callister has noted, “the phrase ‘infinite atonement’ or ‘infinite sacrifice’ may refer to an atonement or sacrifice by a God, a being who is infinite in knowledge, power, and glory…Accordingly, the Atonement is ‘infinite’ because its source is ’infinite.’” (The Infinite Atonement, p. 58)
Bruce R. McConkie
“When the prophets speak of an infinite atonement, they mean just that. Its effects cover all men, the earth itself and all forms of life thereon, and reach out into the endless expanses of eternity….Now our Lord’s jurisdiction and power extend far beyond the limits of this one small earth on which we dwell. He is under the Father, the creator of worlds without number (Moses 1:33). And through the power of his atonement the inhabitants of these worlds, the revelation says, ‘are begotten sons and daughters unto God’ (DC 76:24), which means that the atonement of Christ, being literally and truly infinite, applies to an infinite number of earths.” (Mormon Doctrine, pp. 64-5)
Russell M. Nelson
“His Atonement is infinite—without an end. It was also infinite in that all humankind would be saved from never-ending death (see 2 Nephi 9:7; 25:16; Alma 34:10,12,14). It was infinite in terms of His immense suffering. It was infinite in time, putting an end to the preceding prototype of animal sacrifice. It was infinite in scope—it was to be done once for all (see Heb 10:10). And the mercy of the Atonement extends not only to an infinite number of people, but also to an infinite number of worlds created by Him (see DC 76:24; Moses 1:33). It was infinite beyond any human scale of measurement or mortal comprehension. Jesus was the only one who could offer such an infinite atonement, since He was born of a mortal mother and an immortal Father. Because of that unique birthright, Jesus was an infinite Being.” (Ensign, Nov. 1996, p. 35 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 114)