Dimming light with a for loop

Hi guys, can anyone of you lovely people shed some light on why this does not work?
I’m trying to dim a light using a for loop (yes, I know I can do it with the timeline as well:P), but I cant get it to work properly. Currently, as soon as the delay of 2 seconds has passed, the light just goes dark. Is this because the foor loop runs before anything else, preventing me to see the light dim in action?

There’s no delay inside the loop… it just executes the entire thing at once. Use a timeline.