Our body is like a washing machine, our mind is like cloth, each lifetime is one run or cycle, and Knowledge is detergent. The mind comes into the body to get cleansed and pure. But instead of detergent, if you use dirt, then you have dirty clothes.
Pure water is like love, Knowledge is like detergent, mind is like cloth, and the body like the washing machine. If you put in mud instead of detergent, your clothes become dirtier than before.
You will have to go on putting clothes in the washing machine to get them cleaned. And the process repeats again and again. Similarly you will have many more births until you stop repeating the mistakes that you have made.