Many fake religions don't even have a word for sin. Karma? Yes, but that is not sin. The Bible states it straight out:
Hebrews 9:27 And as it is appointed unto men once to die, but after this the judgment
Jesus did not need to die billions of times to accommodate all the sins of everyone because Jesus was fully human and therefore can only die once. But Jesus is also fully God which means that something quite remarkable happened. Sometimes (in "the Reiki" for example) karma is personified. They insinuate that "Lords of Karma" exist in some discarnate form they have never demonstrated to be real, supervise reincarnation according to past and future requirements for one's souls' development. Karma thus has been embodied many times.
And here The Bible is explicit. Yes, sin has been embodied, but only in a single person NOT in multiple recycled lords of karma.
II Corinthians 5:21 - 6:1 For †he hath made ‡him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. We then, as workers together with him, beseech you also that ye receive not the grace of God in vain.
Karma has nothing to do with grace: everyone gets their just deserts (according to the disembodied lords of) and there is no room for Salvation because there is no time. Just an infinite sequence of events with no transgression by a single wretch blasting all her husband's line into well-deserved torment for ever and ever, over and over again, worse tomorrow than yesterday, never familiar enough to be tolerable, anguish new every morning. There is no BEFORE we were redeemed and no AFTER since the cycle of rebirth continues and rotting corpses float down their special magic river; it sounds like a metaphor, but it isn't. It's real.
Jesus loves us. When He returns He will attend to everyone rejecting His invitation. It's amazing that even after it's been explained how perfect His love really is, how much He suffered actually BECOMING sin so that God could KILL HIM just because He loved us so much, explained to them what happens if this gift is not accepted, still people turn away from the opportunity of Salvation, sneering, "That's not love!" they say. They think they're safe but they won't be sneering much longer.
I Thessalonians 5:3 For when they shall say, Peace and safety; then sudden destruction cometh upon them, as travail upon a woman with child; and they shall not escape.
† God
‡ Jesus