# there are eunuchs who were made eunuchs by men
"there are men whom other men have made eunuchs"
# eunuchs who made themselves eunuchs
Possible meanings are 1) "men who have made themselves eunuchs by removing their private parts" or 2) "men who choose to remain unmarried and sexually pure."
# for the sake of the kingdom of heaven
"so they can better serve our God in heaven"