They should've continued preaching what biblical marriage is for the last half-century. Now that most Catholic couples you meet aren't any more married than two lesbians in a civil union, the advent of "gay" marriage is not the homosexual's fault. The blame rests squarely with the bishops. They taught us only what our itching ears have wanted to hear for 50 years. All of us will now be relegated to ride out centuries of marital chaos, 1,000 English priests' signatures notwithstanding. The bloodshed of Catholics will likely be the cost to reestablish the unprecedented 1,600 years of stable Christian marriage in the West.
The Cornelius debate below highlights what is a "matter of fact" Issue in the churches, namely
1] Did God write the Bible?
2] Can all mortals read the Bible?
Ans 1] The Elect alone are convinced by the Holy Spirit that God did write the Bible.
Ans 2] The Elect alone are provided with the capacity to receive and know the TRUTH by the Holy Spirit.
PRE-Holy Spirit intervention, the mortal can do absolutely zero to know God and Truth. This is the natural estate of the unsaved human condition.
When God calls His Elect to serve, worship and fear God then HE does what is known as regeneration or effectual calling. To achieve this in any mortal God the Holy Spirit works in the heart and mind of the sinner. Without this divine work the sinner is a dead enemy of God.
Some in the church are dead enemies of God as Christ illustrates in Matt 7:21-23. The power of sin and Satan bring them to church as part of the trial and test of the Faith of the True Church. Tares among the wheat.
14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
36 If the Son therefore shall make you free, ye shall be free indeed