Then Jesus said to the crowds and to his disciples:
"The teachers of the law and the Pharisees sit in Moses' seat. So you must obey them and do everything they tell you. But do not do what they do, for they do not practice what they preach. They tie up heavy loads and put them on men's shoulders, but they themselves are not willing to lift a finger to move them."
This has been explained many times on this thread, but you're new so I'll explain it again.
"Do what they say and not what they do" would describe how a Catholic should deal with sinful, humanly flawed popes, bishops and priests. It is referring to men who are hypocrites, who SAY the right thing and teach the true doctrine but who don't live up to it in their own lives. Perhaps they are greedy, or gluttonous, or lustful. Read about Pope Leo X, a very worldly man.
But we are not dealing with sinful Catholics in the throne of Peter today. We are dealing with people who are not Catholic. These are Satanic infiltrators, wolves in sheeps' clothing, they preach the doctrine of the secret societies which is Luciferianism, breaking down Catholicism from within, gradually and ever so slowly.
You can't do what they do ( like pray with false religions ) OR what they say, by believing in their heretical jibber-jabber. But then no one CAN believe in what they say, because what they say is contradictory and makes no sense -- it is the truth mixed with lies, their technique to demoralize and confuse.
What they do, how they operate, is much like the technique of a cobra that stares you in the eyes and hypnotizes you with its eerie beauty, so that you are frozen when you should be running as fast as you can.
You think "Hey, that sounds orthodox, what he just said there," and it paralyzes you... And then the poison is injected into your veins. This has been done slowly for over a hundred years. It didn't begin with Vatican II. People gradually got used to Judeo-Masonic democracies, to the separation of Church and state, to other watered-down doctrine, and to my new personal bugbear, the rhythm method or NFP. The cobra struck again and again and again until people didn't even know they were carrying around a load of fatal poison.
The Catholic Church is the spotless and immaculate bride of Christ -- it is pure truth, with no admixture of lies. We must hold to the true doctrine no matter how strong the suction is towards the lie, no matter even if the whole world believes the lie. And I will tell you, it is pretty close to the whole world that believes the lie today.