Celibacy is a discipline, not doctrine. So is fasting. Both particular Church traditions (East and West) require them to different degrees (Orthodoxy being stricter on fasting and the Roman Catholic side being stricter on celibacy of its clergy).
Both disciplines have their roots in Scriptures, but the Scriptures do not specify the degree to which they are to be practiced.
Discipline aims at resisting passions, as passions lead us into sin. How successful we are in those disciplines depends on one's spiritual state. How well we do is an indicator of where we are spiritually when it comes to resisting evil.
It is a litmus test of theosis, and is intimately connected with the Lord's commandment to repent. Our rejection of evil starts with true and honest repentance, and continues with disciplines that resist passions, confession, fasting, celibacy, etc.
Which gives me another excuse to cite my favorite passage on theosis:
2 Grace to you and peace be accomplished in the knowledge of God and of Christ Jesus our Lord: 3 As all things of his divine power which appertain to life and godliness, are given us, through the knowledge of him who hath called us by his own proper glory and virtue. 4 By whom he hath given us most great and precious promises: that by these you may be made partakers of the divine nature: flying the corruption of that concupiscence which is in the world. 5 And you, employing all care, minister in your faith, virtue; and in virtue, knowledge; 6 And in knowledge, abstinence; and in abstinence, patience; and in patience, godliness; 7 And in godliness, love of brotherhood; and in love of brotherhood, charity. 8 For if these things be with you and abound, they will make you to be neither empty nor unfruitful in the knowledge of our Lord Jesus Christ. 9 For he that hath not these things with him, is blind, and groping, having forgotten that he was purged from his old sins. 10 Wherefore, brethren, labour the more, that by good works you may make sure your calling and election. For doing these things, you shall not sin at any time. 11 For so an entrance shall be ministered to you abundantly into the everlasting kingdom of our Lord and Saviour Jesus Christ.(2 Peter 1)
Thanks for the clarification on discipline. So here, as a discipline it "could" be changed. Kolo spoke earlier about Orthopraxis, and that it includes some disciplines, implying not others. He also spoke of "economia" in the context of a Bishop to one of the laity. I was wondering if this also works from Bishop to priest. For example, if a married priest was being considered for elevation to Bishop, could economia be used to allow it? Or, would this simply never happen?