Jesus said that a person must be born of water and the Spirit to enter the kingdom of God (John 3:5). Throughout the book of Acts we read of people being baptized in water and receiving the gift of the Holy Spirit. Both experiences are necessary for salvation. In addition, the common experience of those who received the Spirit in the Bible was speaking in tongues (see Acts 2:1-4; Acts 10;44-48; Acts 19:1-6). This does not mean that being water baptized and receiving the Spirit is all that is necessary for salvation. To be saved a person must also live by faith, since we are saved by grace through faith.
Please read our articles on this subject in the Apostolic Free Library on Shelf 1, Doctrine.