It's an interesting meditation: how "angels" are at the base of certain religions that've splintered from or are wholly different than original Christianity.
For example, there is Mormonism -- on the surface, a Christian faith, and perhaps, in its essence, if Christ is truthfully acknowledged, it is that.
But there are questions, for sure. Mormons follow practices that are quite apart from those of other Christians, and certainly at variance with Catholicism. It is based on the revelations of an American named Joseph Smith, who basically wrote his own "new testament." His inspiration was an alleged "angel" named Moroni who appeared to him in Upstate New York. Perhaps it was an angel. Perhaps not.
Scripture tells us two things in this regard: that anyone who alters what is in the Bible is not authentically of the Lord, and that "Satan disguises himself as an angel of light" (2 Corinthians 11: 14-15).
This isn't to imply that Mormonism is of the devil. God knows! But it does make one wonder, at the least, about dilution.
There is Islam. Muslims claim their religion -- far more at variance with Christianity than is Mormonism -- derived from visits from the Archangel Gabriel to Mohammed. Did it? Would Gabriel deny (as Islam does) the Divinity and Resurrection of Christ?
We should seek common ground with Muslims, while conceding nothing. One patch of common ground is a single Godhead (if Allah is the same God). Here is the test: by the fruits of a religion do you know it. "Therefore it is not surprising if his servants also disguise themselves as servants of righteousness, whose end will be according to their deeds" (says 2 Corinthians).
Islam cannot be accepted on a par with Christianity, though its good and devout and peaceable followers should be embraced. It is with them -- not with ISIS, not with followers of an Imam in Florida -- that we look for commonality. Is it a problem religion? Very definitely, and has been for many centuries. How many have Muslims killed? Millions (see here).
There are the Jehovah's Witnesses -- in many ways admirable people: dedicated, well disciplined, well dressed, excellent at evangelization (running circles around Catholics in this regard), and sincere. But also different -- in profound, troubling ways -- from other Christian denominations. The main breach: Jehovah's Witnesses believe that Jesus and the Archangel Michael are one of the same entity. Seventh Adventists believe much the same.
What Michael are they talking about?
It is a simple answer: Jesus would not have to call on the name of anyone else in order to rebuke the devil because He was God in flesh. But we see that Michael the Archangel said, "The Lord rebuke you" (Jude 9), thereby demonstrating that he is not the Lord. Anyone who distorts or excises parts of Scripture, we're admonished, is in spiritual jeopardy.
In Scripture, angels certainly play a major role, including Gabriel, who appeared to the Blessed Mother. She saw him before she saw Jesus. He informed Mary of God's incredible designs. An angel spoke to Joseph, warning him. Angels ministered to Jesus in the desert, and moved the stone at the Tomb. Important roles -- vital -- at the base of our faith. But not the foundation of it. Gabriel announced Jesus -- he didn't take His place.
The founder of another "religion," Scientology, was L. Ron Hubbard, who described his angel as a beautiful winged woman with red hair, calling her "Empress," a spirit that apparently guided him through his life, and saved him many times. Hubbard (a Rosicrucian) was outright connected with practitioners of black magic (look up the name Jack Parsons). "If anyone or an angel from Heaven should proclaim to you a gospel contrary to what we proclaimed to you, let that one be accursed," states Galatians 1:8.
Maybe, in this era of anything goes, in this era of Orlando, in this era of Syria-Iraq-Iran, tough stuff is what we need.