“The Lord hath said he dwelleth not in unholy temples.” That is, “the Spirit of the Lord doth not dwell in unholy temples” (Helaman 4:24; emphasis added) “but in the hearts of the righteous doth he dwell.” The Spirit of the Lord can dwell in our hearts. As Doctrine and Covenants 130:3 teaches us, that is a symbolic dwelling in one’s heart, not a literal one (see also D&C 130:22).
On garments being made white through the blood of the Lamb, see commentary at 1 Nephi 12:10–11.