Satan is very happy. He cleverly attacked the theology first. The master deciver made sure there were plent of alternative "Gospels" to go around, and ever since then has been popping up heresies and protests, reforms, what not, even among the brothers.
I would be more concerned about your brothers who run around praying to apparitions of a dead human than those who bury their nose in Scripture and discuss proper understanding.
1 John 2...
Little children, it is the last hour; and as you have heard that Antichrist cometh, even now there are become many Antichrists: whereby we know that it is the last hour. They went out from us, but they were not of us. For if they had been of us, they would no doubt have remained with us; but that they may be manifest, that they are not all of us. But you have the unction from the Holy One, and know all things.
Douai Notes.... 18 "It is the last hour"... That is, it is the last age of the world. Many Antichrists, that is, many heretics, enemies of Christ and his church, and forerunners of the great Antichrist.
19 "They were not of us"... That is, they were not solid, steadfast, genuine Christians: otherwise they would have remained in the church.
20 "The unction from the Holy One"... That is, grace and wisdom from the Holy Ghost.
20 "Know all things"... The true children of God's church, remaining in unity, under the guidance of their lawful pastors, partake of the grace of the Holy Ghost, promised to the church and her pastors; and have in the church all necessary knowledge and instruction; so as to have no need to seek it elsewhere, since it can be only found in that society of which they are members.
*I find it risible that today, I am routinely accosted by Satan's Mini-Me's who preach to me a new Gospel and try to cleave me from the Church established by Jesus when it is palpably obvious I am cleaved to Jesus in His Church.
Satan's Mini-Me's want me to walk the plank off the Barque of Peter. They try and convince me the satanic shark-infested water the Ark of Salvation sails safely over really is the source of my Salvation. All I have to do to join them is to walk the plank off the Barque of Peter and be Baptised in the waters of sola scriptura, self-rule, self-delusion and self-will. Of course, I recognise that apart from Jesus and His Ark of Salvation, I would drown in the sea of delusion and deception. I would find myself cleaved to the deracinated, dessicated, and destroyed denizens of delusion at the bottom of Satan's Sea; Luther, Zwingli,Melanchton, Huss, Beza, Knox,Bucer, Cranmer,Oecolampadius,Ochin, and on and on and on.
Are they convincing me? Not so much...