When He entered the temple, the chief priests and the elders of the people came to Him while He was teaching, and said, “By what authority are You doing these things, and who gave You this authority?”
Jesus said to them, “I will also ask you one thing, which if you tell Me, I will also tell you by what authority I do these things. The baptism of John was from what source, from heaven or from men?”
And they began reasoning among themselves, saying, “If we say, ‘From heaven,’ He will say to us, ‘Then why did you not believe him?’ But if we say, ‘From men,’ we fear the people; for they all regard John as a prophet.”
And answering Jesus, they said, “We do not know.” He also said to them, “Neither will I tell you by what authority I do these things. Matthew 21:23-27
If the Catholic Church is wrong in its theology about such questions as the Trinity, the virgin birth of Christ, the changing of bread and wine into the body and blood of Jesus, or the authority given by Christ to the popes, then it is reasonable to believe the Church can also be wrong about other questions; for example, its position on same-sex marriage and abortion.And if the Church is wrong about its theology, then it ought to be intuitive that Catholics don’t need to obey any of its teaching because her entire structure is a house of cards. We can believe as we wish, do as we wish, and vote as we wish.
But if the Catholic Church is right in its theology, then it is reasonable to believe the Church is also correct in its stand on such social issues – divisive though they may be – as same-sex marriage and abortion.
And if the Church is right, then it ought to be intuitive that Catholics must obey its decisions, because to disobey is to stand against Christ Himself.
It’s all really very simple. As in the discourse recorded in St. Matthew's gospel above, if the baptism of John was from heaven, then Jesus required His hearers to obey what John taught. Likewise, if the teaching of the Catholic Church is from heaven, then Jesus requires those who call themselves Catholics to obey what the Church teaches.To do otherwise can have some very unhappy and eternal consequences.