Read the words carefully. They refer to the symbols on the walls: there's an hourglass in the bottom left that could represent time, for example.
Touching symbols changes which ones are illuminated. For example, at first only the scales are lit, and when you touch it the light moves to the harp on the right. If you touch the harp, the bow and arrow in the bottom right and the hourglass in the bottom left become lit. Touch the bow and arrow, and the scales light up.
What do you think happens when you touch the hourglass? Well, why not give it a go?
With the puzzle in its starting state, touch the scales, the harp, the bow and arrow, and then the hourglass. On this last step, the lights on the scales and hourglass go out and the lights on both the harp and the bow and arrow come on. Or, as the puzzle says: "time changes everything".
Now look at the last three lines. They don't include steps that you can follow, but they're still asking you to do something...
By now you should know how the various lights work, and in fact, if you followed the steps listed in Hint 3, you'll be very close to the answer.
Make sure that only the harp and the bow are lit, then consider the line "hope comes when only time remains". Can you see what you have to do to have the hourglass lit up all on its own?