[ 1 Timothy 3:2
A bishop then must be blameless, the husband of one wife, vigilant, sober, of good behaviour, given to hospitality, apt to teach; ]
There were married catholic priests until Rome saw them as a threat due to the “family lineage” issue and put pressure on the church for only single men to be priests.
Yes. But I’ll put that one little verse against the cardinal’s whole book and 1000 years of tradition and I win the debate.
And some of the Pope’s had mistresses and children.
The Church in the West had to wage a protracted struggle against secular power. Bishops and abbots owned estates, whose income constituted the main support of the Church, but as owners of land in the realm, there were constantly pressured to become mere vassals to the king and way too enmeshed with the political nobility. (Look up “Investiture Controversy” and you will see that reforming popes struggled AGAINST this for centuries.)
If a bishop had sons and daughters, he’d be even more deeply caught up in dynastic marriage politics: marrying this daughter to that duke, and this son to that princess, and forming alliances with powerful families for all the political/economic/social benefits that would accrue.
Trying to secure the independence of bishops from the temporal Powers That Be was a huge job. It took a millennium to settle and it’s not what I’d call “settled” even yet. But, for many centuries in the history of the Church, marriages would have forced priests and, even more so, bishops and abbots, to become even more deeply enmeshed in securing titles of nobility, access to estates and lands, royal alliances and the rest of it for all their children.
The Church was trying to steer clear of that whole web of worldly entanglements. Celibacy --- the avoidance of ongoing dynastic interconnections --- became an honorable way to secure more political independence from worldly preoccupations and temporal power, and hence more freedom to be "in this world but not of it."
It has also the value of "eschatological witness," which means they were dramatically demonstrating that they expected to receive full recompense in the next world, not this one. Check out Mark 10:29-30 (Link)