Well, I believe in Jesus. Why would I need to be baptized?
There are many people nowadays that may have this sort of attitude when it comes to the gift of Holy Baptism. What does Baptism give me that I really need?
God has made promises. But how do you know they apply to you? Who are you that the Holy Promises of God should also include you? Here is the eternal refuge of Holy Baptism. All the promises of God are poured upon you in the water and Word of Baptism. When that water touches your body, immediately you are certain - God has promised these things to me. Personally. This IS faith. The devil might attack my faith and make me doubt whether I believe. My sin might rise up and make me feel dirty and unworthy. Death may stare me in the face and cause me to fear. And in all those moments, the Evil One will press hard to take Jesus away from me. But the One thing he can never change is that God has washed me in water and the Word. God's promise that I am His child, forgiven, justified, sanctified in the Name of Christ and by His Spirit, will always apply to me - because I got wet.
So God has given you baptism as the place you can forever return to Him. He has put Jesus in the water. He has given you a place to drown your sin, to cast off old Adam's works, and emerge new in Jesus. No matter what the devil may throw at you, or whisper to you, or remind you of - you may always say in return, "I am baptized!"
But I believe in Jesus. Why would I need to be baptized? How about another look?
Jesus said, "Unless you are born of water and the Spirit you will never enter the kingdom of God."(John 3:5) Jesus tells us baptism is necessary. Yes, God can save those who have not been baptized, those who have not had the opportunity to be baptized (like the thief on the cross), but that is not what He wants. God commands us to be baptized. He has given us baptism for this reason. To save us (1 Peter 3:21) Faith responds to that command in faith - it gets baptized.
He also said, "Whoever believes and is baptized will be saved, but whoever does not believe will be condemned." The certainty of this Word is for those who believe and are baptized. They will be saved. There is also certainty for those who do not believe. They will be condemned. But where is the certainty for those who believe, but are not baptized? What!? They won't be condemned? That is the best we can contrive from these words. And here is the kicker - how do you know that you believe? This is what the devil will immediately throw at you in any moment of weakness. Well, I believe that I believe. But how do you know you believe that you believe? Faith becomes faith in faith - not in Jesus.
But God has given us baptism. New birth. His Spirit. And He wants us to run to it. The Devil cannot go there - all he can do is tell people that they don't need it.
In closing hear the words of St. Paul to Pastor Titus, "[God] saved us, not because of works done by us in righteousness, but according to His own mercy, by the washing of regeneration and renewal of the Holy Spirit, whom He poured out on us richly through Jesus Christ our Savior, so that being justified by His grace we might become heirs according to the hope of eternal life." (Titus 3:5-7)
Grace is free, offered to you in the Holy washing of Baptism.