I inadvertently completed most of Destiny on Easy mode/level; is there no way to re-trying in “Normal” and then “Hard”? I really don't want to go back to the beginning for the third time...
The easy and hard mode was a mode that was during year 1 of Destiny as levelling was different.
When The Taken King was released and therefore the start of year 2 the hard mode was removed and replaced with the light level system.
You can create a character and go back through the missions but you wouldn't be able to do the higher light level anyway until you were over level 20 and had gear of the higher light.