1. Tradition and church history hold no authority over Scripture - Sure infant baptism has had a long history, but that has no bearing on what the text of Scripture actually says.
2. There are no examples in Scripture of infant baptisms - yep. Not a single instance.
3. Repentance, faith, baptism is the order commended throughout the New Testament.
4. The connection between circumcision and baptism is very loose. There is a connection. They are both signs of God's covenant with His people. However, Scripture does not make much of this connection.
5. Baptism represents death, burial, and resurrection - as we are immersed into the waters, we are symbolically buried with Jesus in His death, and as we arise we are symbolically united to Him in His resurrection.
On a more experiential note, nothing is more Spiritually powerful to me than to watch a new Christian talk about how God rescued him or her, voice his or her faith in Jesus and see him or her emerge from the water with a big joyous smile!