How do you 'render' a text layer in adobe photoshop 6 to return to airbrushing?

When I work on a project and airbrush first -then throw in some text and then try to return to airbrush it says I must render the layer...I go to layers but in making changes there, I lose some of my project and can't find it again. In Adobe 3,4 %26amp;5 I could move freely back and forth btwn. text. and airbrush..what up??? what is rendering?How do you 'render' a text layer in adobe photoshop 6 to return to airbrushing?
I believe when you do that there will be a small green check button toward the upper right, if it's there you should just need to click that.