On the "Mormon Transhumanist Association Response" web site, Vblogger, who is a Mormon, questions why Mormon Transhumanists think we should try to use science and technology as means for transfiguration and resurrection to immortality. He demonstrates that the scriptures teach that God has already transfigured or resurrected persons in the past, and he asks: why would it make sense to use gradual means, like science and technology, to accomplish something God's already accomplished before.
From a Mormon theological perspective, the answer is simple: because the purpose of life is to learn to become as God, it would defeat the purpose if God does for us what we can do for ourselves. We cannot learn that which is done for us. God provides only means, and expects us to do the rest. As we are saved by grace after all we can do; conversely and complementarily, within the context of grace, we are saved by works. These ideas are found all throughout the scriptures. Here is a particularly good passage on this subject from the Book of Mormon:
"And now, my beloved brethren—for ye ought to be beloved; yea, and ye ought to have stirred yourselves more diligently for the welfare and the freedom of this people; but behold, ye have neglected them insomuch that the blood of thousands shall come upon your heads for vengeance; yea, for known unto God were all their cries, and all their sufferings—
"Behold, could ye suppose that ye could sit upon your thrones, and because of the exceeding goodness of God ye could do nothing and he would deliver you? Behold, if ye have supposed this ye have supposed in vain. ...
"Or do ye suppose that the Lord will still deliver us, while we sit upon our thrones and do not make use of the means which the Lord has provided for us?
"Yea, will ye sit in idleness while ye are surrounded with thousands of those, yea, and tens of thousands, who do also sit in idleness, while there are thousands round about in the borders of the land who are falling by the sword, yea, wounded and bleeding?
"Do ye suppose that God will look upon you as guiltless while ye sit still and behold these things? Behold I say unto you, Nay ..." (Alma 60: 10-11, 21-23)
Moving beyond Mormon scripture, to more general theology, it's worth noting that Vblogger's question and questions like it have been asked for millennia, and they have resulted in what is known as the "problem of evil". Basically, the problem is that it seems contradictory that an all-powerful and all-loving God would create a world with misery and pain such as the one we now experience. Why wouldn't an all-loving God want to prevent all the misery and pain? Why wouldn't an all-powerful God be able to do so? More to the point, why didn't God make us all immortal to start with? More than a few persons have considered this problem and concluded that God does not exist.
Mormonism, perhaps better than any other major religion, is well positioned to respond to the problem of evil. Our theology posits a God that, although powerful, was not always God and did not create everything from nothing. This implies some limitations. Moreover, our theology posits that God's purpose is to help us become Gods, joining in God in the fullest sense, rather than merely to enjoy some simple happiness in any lesser extent of flourishing. Mormon scripture also teaches that God is willing to go to just about any extent to help us achieve our potential:
"How oft have I called upon you by the mouth of my servants, and by the ministering of angels, and by mine own voice, and by the voice of thunderings, and by the voice of lightnings, and by the voice of tempests, and by the voice of earthquakes, and great hailstorms, and by the voice of famines and pestilences of every kind, and by the great sound of a trump, and by the voice of judgment, and by the voice of mercy all the day long, and by the voice of glory and honor and the riches of eternal life, and would have saved you with an everlasting salvation, but ye would not!" (D&C 43: 25)
So let's return to Vblogger's original question: why does it make sense for theists to try to learn to do things they think God can already do? Maybe it doesn't make sense unless you also happen to be a theist that trusts in a God that wants you to become God too. In that case, we should expect God to do no more than necessary, even allowing us to fail to varying extents, as we learn to become Gods ourselves, the same as all other Gods have done before.