offered, often with laypersons leading the prayer and the rest of the congregation audibly participating. During these corporate prayers, some may pray in tongues. While not in every service, the pastor will pray for the sick. This prayer may include the pastor anointing the sick with olive oil and with the assistance of church elders along with pastoral associates laying hands on the one seeking healing. Architecturally, smaller churches will feature bright lighting, large windows, a simple platform with a pulpit in the center, and an altar ("a bench across the front of the church below the platform"). Larger churches will have direct access from the balcony to the main sanctuary near the platform so that respondents to altar calls can easily come forward, a large open area in front of the platform to accommodate altar call gatherings, and the platform itself is usually large to accommodate a large choir and musical instruments. Because the Assemblies of God practice baptism by immersion, many churches will include a baptistry at the rear of the platform. Structure The Assemblies of God is defined in its constitution as a "cooperative fellowship" of "churches and credentialed ministers". It has a representative form of government derived from presbyterian polity and organized in three levels of administration: congregations, district councils and the General Council. The AG has, however, elements of congregational polity, which are limited by the powers of the districts and General Council to license and discipline ordained ministers. Congregations Self-governing churches The Assemblies of God uses several classifications of congregations based on their level of local autonomy and their relationship to the General Council. Mature, fully functioning congregations are classified as "General Council affiliated churches". These churches are "sovereign" and self-governing, but in matters of doctrine local assemblies are subordinate to districts and the General Council. A church is qualified for General Council affiliated status if it: accepts AG doctrines, adopts a standard of membership, has an active voting membership of at least 20 persons, adopts a governance model that prevents a pastor or governing body from "exert[ing] dictatorial control over a church", has an adequate number of spiritually qualified members to fill the offices of the church, has made provision for a pastor who is a credentialed minister in good standing with the General Council. Each local church operates according to its own bylaws and calls its own pastor. The office of pastor