Baptism with the Holy Ghost is an instantaneous experience wrought in the life of the believer subsequent to entire sanctification. In this baptism, Christ is the agent, the Spirit is the element (Matthew 3:11). The baptism with the Spirit on the sanctified life is accompanied with speaking in tongues: “And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance” (Acts 2:2-4; see also:10:44-47; 19:1-6). The baptism with the Spirit is a baptism of spiritual empowerment for service in the kingdom of God (Luke 24:49; John 15:26; Acts 1:8); it also enables one to minister effectively within the church for the self-edification of the body (1 Corinthians 12:12-28; Ephesians 4:11-16).
Speaking in Tongues always accompanies the baptism with the Holy Ghost. The believer speaks in “unknown tongues” as “the Spirit gives utterance” (Acts 2:4). “Unknown tongues” is distinguished from speaking by the gift of the Spirit in “divers tongues,” that is, in languages that are known to man (Acts 2:6;1 Corinthians 12:10; 14:2). In either case (“unknown tongues” or languages known to man), the manifestation of tongues (and interpretations) is always consistent with Word of God (1Corinthians 14:26). The gift of tongues is a sign to unbelievers (vv. 21-23), but serve also for the self-edification of the believer (v. 4).
Excerpt from the Zion Assembly Church of God Abstract of Faith.