The Book of Mormon teaches clearly…’now is the time for men (and women) to prepare to meet God’. This teaching is more strongly emphasized just two verses later in Alma 34: 35:
“…if ye have procrastinated the day of your repentance even until death, behold, ye have become subjected to the spirit of the devil, and he doth seal you his: therefore, the Spirit of the Lord hath withdrawn from you, and hath no place in you, and the devil hath all power over you; and this is the final state of the wicked.”
The question, then, is why do temple work for the dead? I suppose an argument could be made for doing temple work for the living thus providing a reward system for faithful members, for performing marriage ceremonies and in providing a ‘bonding experience’ for members of the church. However, doing work for the dead contradicts the teachings of the Book of Mormon.