"I cannot marry a Cohen unless he is ready to give up his rights as a Cohen" - I saw this on one of the shidduch web sites. This prompted me to ask you a question: Is there a halachically accepted way to do this, i.e give up someone’s status as a Cohen? The real case is like this: a guy and a girl want to marry each other. He is a Cohen, but baal-teshuva, i.e. he was told that his father’s father was a cohen (observant) by his non-observant mother. She is also a baal-teshuva and has no documental proof that she is jewish, only verbal testimony of her mother and her aunt. She thus had to go through the geirus process. Now my question is: can they marry each other at all? Can he give up his status of a cohen? What are their status if they do marry? Let me know if you need more information, but I really want to find out what the halacha is in this case. Thank you very much,
A kohen cannot renounce his status. He is either a kohen or he is not. In the specific case you mention- since a kohen is not permitted to marry a convert, the marriage of these two people would be halachically forbidden unless more intensive investigation would reveal that the girl was born Jewish and her conversion was superfluous, or that the mother of the kohen was misinformed when she told her son that he was a kohen. It is possible that records previously unavailable are now open so that doubts about personal status can be investigated more thoroughly.