Luke 9

Luke 9:24

For whosoever will save his life shall lose it: but whosoever will lose his life for my sake, the same shall save it.

Cross reference-
D&C 103: 27&28-
27  Let no man be afraid to lay down his life for my sake; for whoso layeth down his life for my sake shall find it again.
28  And whoso is not willing to lay down his life for my sake is not my disciple.