"Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap." - Galatians 6:7
"Then said Jesus unto him, 'Put up again thy sword into his place: for all they that take the sword shall perish with the sword.'" - Matthew 26:52
What's the problem with "karma" generically speaking?
Reincarnation can be more problematic.