:: Sacramental Baptism vs. Accepting Christ

Catholic bloggers lend me your aid! I am in a bible study with some dear mere Christian friends of mine. How does one explain the difference between a sacramental Baptism and simply accepting Christ? What is the difference between what sacramental Baptism and accepting Christ does to one’s soul? Does sacramental Baptism impart sanctifying grace while accepting Christ is the result of actual grace? I mean accepting Christ is the result of a nudge by the Holy Spirit and it does not change the soul in a fundamental manner?

My first thought is that we can’t simply accept Christ without accepting His commandment to be baptized in a sacramental fashion. It is very hard to discuss this without appearing judgemental. Email me with your thoughts or helpful links!