Effortless..

Good intentions might sometimes turn to bad consequences. Causality? Anyway how we can ensure that our deeds have good intentions? Can such intention have a part of selfishness, a little part which would serve as a good feeling for something we did? Which would be in fact a reward (which is in an extreme sense taken for a 'payment'). According to Imanuel Kant we cant such (rewarded) intention take as good. Not the one where we count on the 'reward', nor the one where the reward comes without us counting with that. Then of course the best would be not to know about such 'reward' which nowadays in our 21.century is quite impossible. Or?