The clerical celibacy in the Catholic priesthood is a discipline. Therefore may it be changed, based on the times and circumstances of current generations in accordance with what our present pope and bishops believe is best of the faithful.
In the Greek and Latin churches the discipline is not the same: but in both, the advice of St. Paul served to establish the principle of the expediency of clerical celibacy. With the Greeks, no one, after Holy Orders, is now allowed to marry; but they that already have wives, they may receive Holy Orders, except the bishop, who must always be a single man.
Again, clerical celibacy is a discipline, not a doctrine.
The Church's Scriptures that support Clerical Celibacy:
If possible, Paul recommends living the single life.
8 To the unmarried and the widows I say that it is well for them to remain single as I do.
1 Corinthians 7:8
Paul gives his advice to those who are single.
25 Now concerning the unmarried, I have no command of the Lord, but I give my opinion as one who by the Lord's mercy is trustworthy. 26 I think that in view of the present distress it is well for a person to remain as he is. 27 Are you bound to a wife? Do not seek to be free. Are you free from a wife? Do not seek marriage. 28 But if you marry, you do not sin, and if a girl marries she does not sin. Yet those who marry will have worldly troubles, and I would spare you that.
1 Corinthians 7:25-28
Paul recommends being true to your vocation, whether one is living a married life or single life.
32 I want you to be free from anxieties. The unmarried man is anxious about the affairs of the Lord, how to please the Lord; 33 but the married man is anxious about worldly affairs, how to please his wife, 34 and his interests are divided. And the unmarried woman or girl is anxious about the affairs of the Lord, how to be holy in body and spirit; but the married woman is anxious about worldly affairs, how to please her husband. 35 I say this for your own benefit, not to lay any restraint upon you, but to promote good order and to secure your undivided devotion to the Lord.
1 Corinthians 7:32-35