Most importantly the adult being Baptised needs to be there. The priest needs to be there to Baptise the adult. In some churches a sponsor will be required to help the adult with the service. Parents and family should be there to watch the Baptism of the adult as they are accepted into the family of God.
The special symbols of adult Baptism are the same as an Infant Baptism. The only difference is the way they are presented or done. The water, like in Infant Baptism, symbolises life, cleansing and growth. This will obviously mean more to adults as they have experienced and acted in good and bad ways in their longer life than babies. The Oil of Chrism is representing the adult being Baptised in the Name of God. It is used and placed upon their head exactly like in Infant Baptism. The candle is held by the adult and sometimes by the congregation to symbolise the adults readiness to walk in the light of Jesus and to share that light with the world. Like in Infant Baptism the name the adult has had from the beginning of his life up to the moment of the sacrament of Baptism will be used so that God can identify the adult as a son or daughter of his family. The word of God is represented in the adults Baptism as the readings and Gospel. This has more of an important meaning for the adult Baptism because the adult can understand the meaning of the word of God. As it says in the Bible, man cannot live on bread alone but on every word from the mouth of God.
Baptist, Pentecostal and Methodist Churches all believe in adult Baptism as they think you need to be old enough to make a personal pledge to follow Christ and renounce sin. In a non Catholic Baptism the Baptism is nearly always a full immersion often in a lake or river (sometimes a pool) like Jesus’ Baptism in the River Jordan. The Catholic adults however will usually get Baptised at the time of Easter. As in Infant Baptism they will be...