Mark 1:8 is our study verse today. In this verse, you see the two different ministries of John and Jesus. To make it simple to understand: John's was outward. Jesus' was inward. John's water baptism was an outward sign of an inward reality of the cleansing of sin. Is it important for believers today? I think so. In Matthew 28:19,20 Jesus said the job of the church is to make disciples, "baptizing them in the name of the Father, Son and Holy Spirit." It's a public declaration of our decision of follow Jesus. In the Ethiopian church under persecution in the 1980's, a supposed follower of Jesus was not persecuted until public baptism. At that point, the government knew the seriousness of their walk in Christ. Then persecution began.
But people can be outwardly baptized and it not touch the heart. As important as water baptism is, it should signify Spirit baptism, Jesus' baptism with fire. What does this mean? Probably two things:
1) Jesus' inward baptism of fire that begins the process of burning away all sin when he enters a life. Slowly but surely, as we open doors to rooms filled with the garbage of our lives, he takes this "stuff" to his holy "incinerator" and burns them away. It's an all-consuming fire that wants no sin left in the heart of the person in whom he dwells. My guess is any of you who have invited Jesus to live in your hearts know exactly what I'm talking about.
2) It's the eternal fire of God, God's final judgment that will "baptize", fully consume all unbelievers at the Final Judgment. People who don't believe in Jesus will be cast into "the lake of fire" (see Revelation). God will not tolerate any evil in his presence.
John's and Jesus' baptisms are important for the follower of Jesus. The first one is the inward baptism of fire, then naturally followed by the public expression of faith in the second.
Both are necessary. Have both happened to you?