A lot of "truthers" unfortunately get led astray into various false paths and dead-ends, due to a lack of guide (the Catholic Church).

Many "truthers" who are good on various cօռspιʀαcιҽs (the Jєωs, Illuminati, Freemasons, etc.) as you describe unfortunately get led astray due to various teachers out there, who assign fault to the Jesuits for example. They throw the Jesuits and The Vatican in there with all the other bad guys.

It's sad, because these guys started out innocent and with good will, and possibly are STILL good willed, but unfortunately they've been duped, objectively speaking. And now they think the Catholic Church is part of the conspiracy to "deceive humanity", and thus part of the enemy that must be fought.

It's actually quite frustrating.

The first starting-point for anyone who would seek the truth is GOD, who can neither deceive nor be deceived. And by many rational arguments, we know that God wants to be worshiped and there is only ONE way to worship God, that Jesus Christ is a historical figure, God and man, Who came and redeemed us and did something no other man had done, namely rising from the dead. And it was THAT miraculous start that caused the Catholic Faith to spread throughout the world, the work of 12 uneducated, blue-collar men. And unlike Islam (for example) they didn't spread the Faith with the sword, which would be a good human cause or explanation. The spread and growth of the Church was miraculous? you bet. And it doesn't end there -- the continued existence and SURVIVAL of the Church over the past 20 centuries also bears out its claims to be the one Church founded by Christ. And then there are the countless miracles and holy men and women, fruits of holiness, that have sprung from the Holy Catholic Church over the centuries...

It is only by starting there, that there is one God, whose Son redeemed us and set up a Church, that we have any hope of navigating all the deceptions out there, set up by men and the fallen angelic intellects (devils).

I am thinking about bringing in some Papal Encyclicals on Fɾҽҽmαsσɳɾყ, not to be contentious, but he might actually read them.  And see that Traditional Catholicism knows ALL about Freemasons... the Church's visible arch-enemy (front for тαℓмυdic Jєωs).

Probably not a bad idea vis-a-vis attempting to convert the individual.  If he's on to Fɾҽҽmαsσɳɾყ, there's plenty of evidence that can be found that the Masons had the Catholic Church as their number one target for destruction.  Why?  That might help open his eyes a bit, naturally speaking, though of course it's all about the working of God's grace, so Masses offered for his conversion might bring him the efficacious grace for his conversion (and would certainly bring sufficient grace).  So the Alta Vendita might be good ... as per Univocity's recommendation above.  There are a few good books written by Catholics about the infiltration of Fɾҽҽmαsσɳɾყ into the Church also.

https://ia904609.us.archive.org/23/items/Fɾҽҽmαsσɳɾყ-unveiled/Fɾҽҽmαsσɳɾყ%20Unveiled%20-%20By%20The%20Cardinal%20Of%20Chile%20%281925%20%26%201957%29.pdf

A lot of "truthers" unfortunately get led astray into various false paths and dead-ends, due to a lack of guide (the Catholic Church).

Many "truthers" who are good on various cօռspιʀαcιҽs (the Jєωs, Illuminati, Freemasons, etc.) as you describe unfortunately get led astray due to various teachers out there, who assign fault to the Jesuits for example. They throw the Jesuits and The Vatican in there with all the other bad guys.

It's sad, because these guys started out innocent and with good will, and possibly are STILL good willed, but unfortunately they've been duped, objectively speaking. And now they think the Catholic Church is part of the conspiracy to "deceive humanity", and thus part of the enemy that must be fought.

It's actually quite frustrating.

The first starting-point for anyone who would seek the truth is GOD, who can neither deceive nor be deceived. And by many rational arguments, we know that God wants to be worshiped and there is only ONE way to worship God, that Jesus Christ is a historical figure, God and man, Who came and redeemed us and did something no other man had done, namely rising from the dead. And it was THAT miraculous start that caused the Catholic Faith to spread throughout the world, the work of 12 uneducated, blue-collar men. And unlike Islam (for example) they didn't spread the Faith with the sword, which would be a good human cause or explanation. The spread and growth of the Church was miraculous? you bet. And it doesn't end there -- the continued existence and SURVIVAL of the Church over the past 20 centuries also bears out its claims to be the one Church founded by Christ. And then there are the countless miracles and holy men and women, fruits of holiness, that have sprung from the Holy Catholic Church over the centuries...

It is only by starting there, that there is one God, whose Son redeemed us and set up a Church, that we have any hope of navigating all the deceptions out there, set up by men and the fallen angelic intellects (devils).

 
It is ironic that a counter-cultural religion from the Levant, with roots in Judaism, would sweep pagan Europe and transform it into the most excellent culture the world has ever known, making it into an engine which brought both civilization and the Faith to a huge part of the rest of the world (the Americas, Oceania, and now increasingly, sub-Saharan Africa).  The latter process was not perfect, but it was a vast improvement over the paganism, and often savagery, of those areas.