Our body is like a washing machine. Our mind is like cloth. Love is like pure water. Knowledge is detergent. Each lifetime is one wash cycle.
The mind comes into the body to get cleansed and pure. But if you put in mud instead of detergent, your clothes become dirtier than before. You will have to go on putting your 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.