Sara Urry, the difference is that other religions don't impose their beliefs on other religions while Mormons do by the very act of baptizing people by proxy who would not have consented while they were still living. (religion.blogs.cnn.com)
His challenge is stark and stunning: Before ordering that the Gentiles be baptized Peter asks «Can anyone withhold the water for baptizing these people who have received the Holy Spirit just as we have?» (religion.blogs.cnn.com)
«The matrimonial covenant, by which a man and a woman establish between themselves a partnership of the whole of life, is by its nature ordered toward the good of the spouses and the procreation and education of offspring; this covenant between baptized persons has been raised by Christ the Lord to the dignity of a sacrament.» (faith.org.uk)