What does Jesus mean when he preaches the sermon on the mount (in Matthew 5:29-30) and he says if your right eye or our hand causes you to sin, cut it off and throw it away. Does he literally mean to cut it off? Isn’t that destroying his temple?
The point of his teaching is, “it is profitable for thee that one of thy members should perish, and not [that] thy whole body should be cast into hell.” If the temptation is so extreme and you have tried to overcome it, but the only way to keep from sinning is to cut off a body part, that would be preferable to sinning and suffering for eternity. It is highly unlikely that anyone would have to go to that extreme. If it were necessary, though, one would be better to suffer a little now rather than for eternity.
Would that be destroying his temple? It might be causing harm to his temple, but it would not be destroying it. Taking out a wall that is rotting is sometimes necessary to save a building from being destroyed. Continuing in sin would be destroying the temple. Maiming the body, in the unlikely case that it became necessary, would be saving the temple.
This body may lose body parts and it won’t affect our spiritual bodies. Paul points out in 1 Corinthians 15 that the body we will have is significantly different than the body we now have, just as a flower is significantly different from a seed. What is important is our soul, and not our physical body. That doesn’t mean we should mistreat our bodies, however, because we have to live in them until we are changed.