Pentecostalism is a Protestant Charismatic Christian movement that emphasizes direct personal experience of God through baptism with the Holy Spirit. The term Pentecostal is derived from Pentecost, an event that commemorates the descent of the Holy Spirit upon the Apostles and other followers of Jesus Christ while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles (Acts 2:1–31) . There are approximately 170 different denominations that identify themselves as Pentecostal, and globally, there are 644 million Christians in the Pentecostal movement.

Here are some key beliefs and practices of Pentecostal churches:

• Emphasis on the gifts of the Holy Spirit, such as speaking in tongues and divine healing.
• Belief in the "baptism in the Holy Spirit" that enables a Christian to "live a Spirit-filled and empowered life".
• Adherence to the inerrancy of the Bible and the necessity of the New Birth: an individual repenting of their sin and "accepting Jesus Christ as personal Lord and Savior".
• Most Pentecostals believe in salvation, baptism through the Holy Spirit, healing through Jesus, and the belief that Jesus is returning.
• Faith healing is an important part of the Pentecostal tradition.
• Pentecostals believe that faith must be powerfully experiential, and not something found merely through ritual or thinking.
• Pentecostal churches stress the importance of conversions that amount to a Baptism in the Spirit. This fills the believer with the Holy Spirit, which gives the believer the strength to live a truly Christian life.
• Pentecostalism is not a church in itself, but a movement that includes many different churches. It is also a movement of renewal or revival within other denominations.
• Pentecostals emphasize the teaching of the "full gospel" or "foursquare gospel".
• The majority of Pentecostal denominations believe in the doctrine of the Trinity, which is considered by them to be Christian orthodoxy.
• There are three main divisions within the Pentecostal movement: the original group which came out of the Holiness churches, the Charismatics, and the Oneness Pentecostals.

Overall, Pentecostalism is a movement within Christianity that emphasizes the work of the Holy Spirit and the direct experience of the presence of God by the believer.