As in Solomon's temple, in which the stones had to be joined together without support beams, the living stones in God's spiritual Temple have to be shaped and designed individually (as character is individually developed) so that they can be fitted together at some future point with no friction or glitches. The rough spots (of sin and iniquity) have to be chiseled out and polished; the gaps and cracks have to be filled in. The Master Builder alone knows how to join all the pieces together.