Baptism, in the Gospels

In the Gospels baptising is based on the symbolic practice in the OT and Judaism of cleansing with water.

Washing was the means of achieving ritual purity

Exodus 30:19–20; Mark 7:3–4 The Greek word here translated “wash” is “baptizo”, from which the English “baptise” comes.

Sprinkling with water symbolises spiritual cleansing

Ezekiel 36:25 See also Zechariah 13:1; Hebrews 10:22

I will also sprinkle clean water on you, and you will be clean. I will cleanse you from all your impurities and all your idols.

Being baptised by John was a confession that cleansing was needed

Matthew 3:11 See also Matthew 3:6; Mark 1:4–5 parallel Luke 3:3; Acts 19:1–4

I baptize you with water for repentance, but after me will come One more powerful than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and with fire.

John promised that the Messiah would cleanse with the baptism of the Holy Spirit

Matthew 3:11 parallels Mark 1:8, Luke 3:16 See also Isaiah 44:3; Ezekiel 36:25–26

I baptize you with water for repentance, but after me will come One more powerful than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and with fire.

Baptism involves both water and the Holy Spirit

John 3:5

Jesus answered, “Truly, truly, I tell you, no one can enter the kingdom of God unless he is born of water and the Spirit.

The disciples of Jesus Christ baptised like John's

See also John 3:22–23, John 4:1

Jesus Christ was baptised by John

Matthew 3:13–17 parallels Mark 1:9–11, Luke 3:21–22, John 1:32–33