In order to understand it helps to trace mankind's religious family tree all the way back to its roots in ancient Babylon.
As the pagan peoples migrated from Babylon they took with them their pagan religious concepts and ideas and spread them world wide into a greater religious Babylon or Babylon the Great. Prominent among their beliefs were triune gods or trinity. That is why we see similar religious trinitarian concepts overlapping in the world's religions even today.
After first-century Christianity ended a fusion or mixing of foreign non-Christian religious concepts became blended with existing Scripture creating a religious syncretism. This has resulted in a new teaching, or new belief system, that can Not be reconciled to biblical first-century Christianity.
That 'new' never fully replace the old, meaning Jesus teachings, but the 'new' flourishes as if it was the old or Christ's teachings. Jesus forewarned that many would come 'in his name' but prove false at Matthew chapter 7.
Luke wrote that wolf-like clergy would fleece the flock of God. Acts 20vs29,30
They fleece by teaching non-Christian beliefs as if Christian.
Jesus forewarned us that over the centuries that genuine 'wheat' Christians would grow together with fake 'weed/tares' Christians until the harvest time or end time of evil on earth. In other words, our time frame until the time of separation of the humble sheep-like ones from the goats of Matthew 25vs31,32.
The people of Acts [17v11] searched or researched Scriptures daily to see if what they were learning was really so. Really found in Scriptures or what the Bible really teaches.
