While I understand the desire to have an unmarried clergy, I wonder how the Catholic church interprets 1 Corinthians 9:5, which seems to imply that Peter, the apostles, and Christ's brothers were married. From the NKJV: "Do we have no right to take along a believing wife, as do also the other apostles, the brothers of the Lord, and Cephas?"
That's your first mistake. Using an abridged, edited, corrupted version of a Catholic document, the Bible, as a reference. St.Paul wrote woman, not wife, in First Corinthians
"Have we not power to carry about a woman, a sister as well as the rest of the apostles and the brethren of the Lord and Cephas?" 1 Corinthians 9:5
We know this because St. Paul himself was celibate.
"But I say to the unmarried and to the widows: It is good for them if they so continue, even as I." 1 Corinthians 7:8
You also need to read the following:
"Then Peter answering, said to him: Behold we have left all things, and have followed thee: what therefore shall we have? And Jesus said to them: Amen I say to you, that you who have followed me, in the regeneration, when the Son of man shall sit on the seat of his majesty, you also shall sit on twelve seats judging the twelve tribes of Israel. And every one that hath left house, or brethren, or sisters, or father, or mother, or wife, or children, or lands for my name's sake, shall receive an hundredfold, and shall possess life everlasting. And many that are first, shall be last: and the last shall be first."Matthew 19:27-30
"Then Peter said: Behold, we have left all things and have followed thee. Who said to them: Amen, I say to you, there is no man that hath left home or parents or brethren or wife or children, for the kingdom of God's sake, Who shall not receive much more in this present time, and in the world to come life everlasting." Luke 18:28-30
The discipline of celibacy and the priesthood in the Catholic Church has its origin with the Apostles and finds its genesis with Melchisedech in the Levitical priesthood in the Old Testament.
While I understand the desire to have an unmarried clergy,
I'm curious as to just exactly what it is that you "understand".
Catholics do not believe that clerical celibacy is a divine mandate, but a matter of church discipline and prudential wisdom. Celibacy was not uniformly practiced in the West in the first millenium; there were even a couple of Roman Popes (well after the time of St. Paul) who were married.
Even today, there are married clergy in the Catholic Church. Some of the Eastern Rites ordain married men to the priesthood as customary practice. Western Catholics ordain married men to the diaconate (deacons are technically considered clerics, as well as priests and bishops, and receive the Sacrament of Holy Orders). And some married Protestant ministers who converted to Catholicism have been ordained to the Catholic priesthood.
BTW, it's a matter of some dispute among Scripture scholars whether St. Paul was married. In one place, he seems to say that he wasn't (1 Cor 7:8), and in another place, he appears to address his wife directly. (Philippians 4:3; "true yokefellow" is a Greek idiom for "wife")
There's no conclusive evidence that St. Peter was married after the time he became an Apostle, AFAIK. Scripture mentions his mother-in-law, but not his wife. Tradition mentions his daughter, but, again, I'm unaware that his wife is named. He may have been a widower.
St. Paul makes it very clear in 1 Cor 7 that celibacy is the higher state. Christ was celibate; those who wish to imitate him perfectly should follow his example.
Revelation 14:4 speaks of 144,000 sealed men "who have not defiled themselves with women" for they are "virgins". What significance do you think celibacy has in view of this, St. Paul's praise of celibacy in 1 Cor 7, and Christ's own example?