I agree and think it's very evident in those religions.
I disagree. There's nothing in Christian doctrine to support it. Actually, it's contrary to it. The "golden rule" for example, isn't intended to get something in return for doing good, and it's certainly not a compulsory act for salvation. The Christian God commanded us to love one another, even our enemies, simply because it's the right thing to do.
In the christian sense the golden rule is to extend to others without requisit for return, in the gospel of John, where the "law of ******" is first indocterinated. The "ethic of reciprocity" is amended to include "love one another" also in Matthew and Luke, "turn the other cheek" which ammends again the "ethic of reciprocity" to discount an evil person. So the golden rule doesn't apply to evil people, which is why it's okay to burn witches at the stake, because they are evil.
Where Karma comes in, is more relevant to "Turn the other cheek", "Do not judge, and you will not be Judged..." "do not condemn, and you will not be condemned,..." "forgive, and you will be forgive". (Luke 6:27 & 32) It's indicated that even without reciprocation, you will be rewarded elsewhere in kind, which is Karma.
