The beginning of the Protestant Reformation was attended by an outburst of iconoclasm. Iconoclasm is the removal of statues and images from churches. It was often the occasion in the 16th century of a good deal of religious violence as Protestants frequently broke into churches to smash images, and Catholics tended to defend their churches and purge cities and towns of what they saw as heretics.
Huldrych Zwingli went so far as to have the walls of the Grossmünster in Zurich, which had been a Roman Catholic cathedral, whitewashed. The reason for this iconoclasm was the belief that the promise of salvation through God's gracious forgiveness is most directly and clearly communicated through the scripture—preached, taught, studied, and memorized. Protestants, believing that Roman Catholics had largely wandered from the centrality of the Bible, removed what they saw as distracting and superstitious paintings, statues, and other images that had been substituted for God's word.
Protestant worship space, as a result, is in general characterized by a plainer aesthetic than the space of Roman Catholics or Eastern Orthodox Christians. There is, however, diversity among Protestants. Reformed Christians have more closely followed Zwingli's principle for trying to move church practice back to the model of the early Church found in scripture. Zwingli's principle was that only those things explicitly authorized by scripture were allowed. Though he was himself quite a talented musician, he had pipe organs removed from the former Catholic churches in his synod because pipe organs are not mentioned in scripture. Instead of hymns, Reformed worshippers in Zurich chanted psalms.
Lutherans, in contrast, followed Martin Luther's principle for reforming church practice: anything not forbidden by scripture was allowed. Luther was a fairly conservative reformer in this respect. Lutheran ministers still wore vestments, and organ music and hymn singing played a significant role in Lutheranism. Luther was not as keen on iconoclasm as Zwingli. Anglicans, too, because of the Elizabethan settlement, which forged a compromise between Catholics and Calvinists by adopting a largely Calvinist theology while maintaining a more Catholic worship, have churches that more closely resemble Catholic churches than do those of other Protestants.
Protestants, who view the sacraments differently than Catholics, reflect their beliefs in their sanctuaries. Most Protestants have two sacraments—baptism and the Lord's Supper—rather than seven. (Some Protestants—like the Society of Friends, or Quakers—do not practice any sacraments at all.) Some Protestants, in particular Baptists, some independent churches, and some non-denominational churches, do not call baptism and the Lord's Supper sacraments. They refer to them instead as ordinances.
A sacrament is usually understood as a means of grace; it is an effective channel of divine action. An ordinance, on the other hand, is a human action, a sign or testimony of one's belief. Many Protestants partake in the Lord's Supper because they believe in the forgiveness of sin that was accomplished in Jesus' death on the cross, and sharing the Lord's Supper is a sign of this belief; it does not itself offer forgiveness. Protestants who reject infant baptism do so in part because they believe the individual must make a statement of faith, and that baptism then becomes the public testimony of faith. Thus Protestants view these sacraments as physical manifestations of the verbal promises of God, to which they cling.
These differences are visible in many Protestant sanctuaries. The worship space of Protestants is organized to emphasize the centrality of hearing the word of God. Most conservative Protestant groups have the pulpit in the center of the platform facing the people, thus indicating the centrality of the preaching of the scripture. The altar is often referred to as the Lord's Table, thus eliminating the idea of sacrifice associated with the Roman Catholic liturgy and emphasizing the memorial aspect of much Reformed thinking. For many Protestant churches outside of Lutheran or Anglican traditions, the Lord's Table is below the elevated pulpit or even off to the side of the sanctuary. In any case, it is viewed as another opportunity to experience and trust God's promise of forgiveness, and it requires the congregation's active understanding and participation.
Baptism, a practice of using water to symbolize the washing away of sin, can be done by aspersion (sprinkling water on the head), affusion (pouring water over the head), immersion (partial submersion underwater), or submersion (full submersion under water). Many denominations allow any form of baptism. Some conservative churches practice submersion exclusively, believing it to be modeled on Jesus' baptism by John the Baptist in the Jordan River and therefore more scriptural. These churches often have baptismal tanks near the sanctuary for this purpose.