The pentecostal movement had its origins in believers who were intensely desiring more of God
in the late 19th century. People were getting interested in world evangelization and realized
that they needed the original power of the Holy Spirit to do this. They sought God and prayed.
Many Methodists and Salvation Army people were among those who were most hungry for God, and
embraced the move of the Holy Spirit.
People had been thinking that God no longer spoke except through the Bible, and that speaking in tongues
had ceased, but the early pentecostal pioneers challenged that. No doubt Satan tried to mess with the
pentecostal movement as he does with all churches, but the testimony of the Spirit of God
became too much for staunch conservatives and now the pentecostal/charismatic movement is
established as mainstream evangelical Christianity in all places where the church is growing.
If you can get hold of the book “Pioneers of Faith” by Lester Sumrall you can get
an account from a man who personally met many of the early pentecostal leaders.
I would also recommend books by Gordon Lindsay on the life of Dr John G. Lake, and various books
on the life of Smith Wigglesworth.