IN THE PARSHAH:
Towards the end of פרשת משפטים we learn that the Yidden entered the covenant with Hashem by having a ברית מילה, immersing in a מקוה, and bringing a קרבן (see רש"י כד, ו). The רמב"ם explains that from that time onward, anyone wanting to become a Yid would also be required to do these three things. However, nowadays, since we cannot bring קרבנות, he must have a ברית מילה, and immerse in a מקוה, and when the בית המקדש will be rebuilt, he will have to bring a קרבן.
QUESTION:
If someone becomes a גר nowadays, what will his status be once משיח comes, before he actually brings his קרבן? Since he now has to bring a קרבן, is his conversion considered incomplete until he actually does so?
ANSWER:
Once someone becomes a Yid, it cannot be undone. He is fully a Yid, forever. Therefore, when משיח comes, while he has an obligation to bring a קרבן, this does not in any way change the fact that he is a Yid.
In fact, although when the בית המקדש stood he would not be allowed to partake of any קדשים before bringing his קרבן, someone who becomes a Yid nowadays, will be allowed to partake of קדשים when the בית המקדש is rebuilt, even before he brings his own קרבן.
Further discussion:
Why is it that although when the ביהמ"ק stood one had to bring a קרבן to become a Yid, nowadays ברית מילה and מקוה are sufficient? (See אות ו in the שיחה)
