Converts in Messianic Times?
Reader: I’ve heard some Rabbis say that converts won’t be accepted after Mosciach has arrived, does this make sense to you; do you agree with it?
Rabbi: Talmud Yevamos 24b:
“In Messianic times, converts will not be accepted...as was so in King David’s days and in King Solomon’s days. Rabbi Eliezer asked, ‘What is the scriptural source? ‘Behold they [converts] will surely convert; without Me those who will convert to you will fall into your lot’. (Isaiah 54:15) Otherwise, they will not’.”
Rashi explains “without Me those who will convert to you will fall into your lot” to mean that those who are accepted as converts are those who convert even when God is not with the Jews, i.e., in current times prior to the Messianic era. If gentiles join the Jewish nation while we are yet oppressed, then they will truly join in the Jews and our lot of Olam Haba (afterlife) as all Jews. Attachment to an oppressed Jewish nation must be due to a sincere desire.
But if gentiles convert once we are catapulted to success in Messiah’s times, we are suspicious of an ulterior motive, and we do not accept them. Similarly, in the days of King David and King Solomon converts were not accepted, for thy were suspected of ulterior motivation: desire for power and wealth respectively.
But see Tosfos (Yevamos 24b) who implies that we view each individual based on his own merits.
I cannot offer a definite answer on your question. But I hope this opens the area to your own further study.