How hard is celibacy?

For those whom God is calling to the priesthood, He is giving the grace of celibacy. Like any gift it is not passively received, but is to be actively accepted. The virtue of chastity in the celibate state must be built up. This requires effort and vigilance, but it is not done alone; it is done with the help of God. Jesus answered, “Not all can accept [this] word, but only those to whom that is granted. Some are incapable of marriage because they were born so; some, because they were made so by others; some, because they have renounced marriage for the sake of the Kingdom of Heaven. Whoever can accept this ought to accept it.” Matthew 19:11-12.