One Sunday in 1855, Charles Spurgeon preached a sermon titled "The Power of the Holy Ghost." In the midst of the sermon, he speaks in a manner that can only be described as prophetic, as he speaks of a coming, latter-day outpouring of God's Spirit upon His people.
People being "slain in the Spirit" (also known as "falling under the power) is a controversial phenomenon, but I believe there is sufficient light in Scripture as well as help from history to lead us to some conclusions on the matter.
The modern Pentecostal movement is characterized by the belief in the possibility of receiving the same experience and gifts as did the first Christians on the day of Pentecost.