Often referred to as 'The most powerful weapon in the Universe', the Green Lantern ring seeks out a barer worthy to wield it. The ring is fuelled by the user's will, the stronger one's will the stronger and more versatile the ring can be. From what we've seen; a noob like Simon Baz was able to bring his brother in-law back from a coma simply because he willed it...and I wouldn't nearly consider Simon Baz to be anywhere near top-level Green Lantern. Kyle Rayner was stated to be able to convert water into Gasoline with his ring (or something like that). But just like anybody else, these character's will were fairly limited. Based purely off of speculation; how powerful would a Green Lantern be if their will was limitless?
Could a Green Lantern potentially be SkyFather level if their will was strong enough?