Hi Savic11, and welcome to the forum!
Yes, I know, it hurts to see someone whom you know turn away from the Orthodox faith under the influence of purely emotional, irrational heresies that ignore all history and distort things... Just a short while ago, I wrote to this forum about one of my former students who was raised Methodist and then consciously, as a young adult, converted to Orthodoxy - but then, being in the U.S. army, fell victim of some Charismatic, Pentecostal-like group with their roaring electric guitars, shaking hands in the air, etc. She still is with that group, and I doubt that right now it would help if I or someone else tried to "re-convert" her by "debating" Pentecostalism and "dispelling" the heresies she is "charmed" with... Perhaps people like her, and maybe like your friend, should be given some time so that they would come to their senses on their own.
On the other hand, of course, do make use of the links people generously provided above.
Welcome again, good to have you on board!