I respect your interpretation of the dialogue and I have my own. But I think that the term "light side" is never used while the term "dark side" is used a lot, shows that the Jedi simply view the "light side" as the Force, in it's completeness. The dark side is an unbalance corruption of the Force. If not then Jedi would be saying "Trust in the light side". Obi-Wan would have been telling Luke "Use the light side" during the trench run.