The church altar is the focal point of each church service.

The Christian church year is split up into two main sections: the festival season and the non-festival season. During the festival season, the church celebrates all of its church festivals, including Christmas and Easter. Each season and each individual festival calls for specific decorations on the altar of the church. While these decorations are not necessarily required, many churches use them to reflect the season and celebrate and honor God. Regardless of which denomination the church belongs to, the same basic decoration rules apply for each season.

Decorate with the color blue or purple during the Advent season leading up to Christmas. This season is the preparation of the birth of Jesus. Some churches use blue to signify hope, while other use purple to reflect royalty.

Use white for all major Christian festivals that are directly related to God. This includes Christmas, Easter, Ascension and sometimes Epiphany. White is the symbol of purity and glory.

Adorn the altar with purple during the Lenten season leading up to Holy Week. During this time, Christians reflect on the life of Jesus and his journey to the cross. Purple is the symbol of royalty, but also represents fasting and penitence, which are important aspects of the Lent season.

Place red decorations on the altar for all festivals that relate to the Holy Spirit. The most common days to use this color are Pentecost and any mission festivals.

Decorate the altar with green during the non-festival season. Some churches also use green on Ephiphany and Pentecost instead of white or red. Green is symbolic of the growth of a Christian's faith.

Leave the altar clear of any decoration for Holy Week, including Ash Wednesday and Good Friday. The empty altar symbolizes the sacrifice that Jesus made for all sinners and the unworthiness of sinners. Some churches still decorate with purple for Ash Wednesday and use black for Good Friday instead of leaving the altar empty.

Place flowers on the altar during any season, with the exception of Holy Week, when the altar should remain empty. The flowers can reflect the growing season or match the appropriate church-season color. In some churches, members donate the money to purchase flowers for the altar.