There simply is no water in the verse you just qouted. And, obediance is in the catagory of works. We are not saved by works, but by grace. James says that faith without works is dead, so we need to show our faith by our actions. Translate that Greek word pistis to believing, and it fits.
Baptism is essential.
True, but leave off the water. Actually, faith is a part of the baptism. We obey out of our faith. Faith is more that belief. These are all action items that tell us that faith moved them to do something.