In our liturgical prayers and art, we use several symbols to represent the Holy Spirit, all of them with biblical backgrounds. The fire that appeared on Pentecost was reminiscent of the fire in the burning bush on Mount Sinai from which God spoke to Moses.
Fire calls attention to the strength and force of the Holy Spirit. The wind that appeared on Pentecost was reminiscent of the wind that blew over the waters at the beginning of Creation.
The wind calls attention to the Holy Spirit breathing life into the Church.
Water represents the cleansing and life-giving action of the Holy Spirit at Baptism.
The cloud is used as a symbol of the Holy Spirit because clouds provide life-giving water.
Anointing with oil is a symbol of the Holy Spirit's uniting us with Jesus, the Messiah, the Anointed One.
Official documents carry a seal on them, so the seal is a symbol of the permanent effect of the Holy Spirit on the lives of those who are filled with the Spirit.
The dove is a symbol of the Holy Spirit that comes to us from the story of Jesus' baptism, when Jesus saw "the Spirit, like a dove, descending upon him" (Mark 1:10).