The question is asked: How does the פרה אדומה - red heifer, relate to us today, since even in the times of the Bais Hamikdosh, it was rarely performed? Also, what is the meaning of what we are taught with regard to the Parah that it "purifies those who are טמא - unclean, and makes tamei those who are pure." 

     The Baal Shem Tov zt"l answers that we are referring to the trait of גאוה - conceit, which can be both bad and good. When a person finds himself going on the path away from Hashem, the beginning of his attempt to rectify his situation is through conceit. When one starts to serve Hashem it is not always possible to achieve an understanding that he can do nothing without Hashem. But he must do something. Therefore he must serve Hashem with conceit - to glorify himself and serve Hashem for reasons other then His Name's sake in order that by serving Him for an ulterior reason he may come to serve Hashem for His Name's sake. Later, though, when he has passed this stage, and observing the mitzvos properly, then he must have the correct intentions, pure without any conceit whatsoever. For if he mixes any conceit with his service, it will be invalid. From this we see that conceit makes pure those who are tamei. i.e. those who are far from Hashem since it brings them closer to serving Hashem for His name's sake, but it also makes tamei those who are pure, i.e. those who are already close to Hashem since their service will be rendered invalid.