A lot of people believe that the Luftwaffe could have easily destroyed the RAF

There was no way for the Luftwaffe to easily destroy the RAF. Britain's air defence network, the [Dowding System] (http://www.iwm.org.uk/history/what-was-the-dowding-system), was highly efficient, allowing Fighter Command to focus its resources, and meant that aircraft were seldom caught on the ground. Airfields were hard targets to put out of action for any length of time (craters in grass runways could be quickly filled, personnel and aircraft dispersed), and the RAF had plenty of them; from 8th August to 10th September thirteen 11 Group airfields were attacked over 40 times in total, but only two were unfit for flying for more than a few hours. In the air the Luftwaffe consistently lost more aircraft than the RAF, and British pilots who force landed or bailed out could be back in action the same day as opposed to German aircrew who faced captivity. British aircraft production was ramping up, outstripping Germany (average British monthly production of fighters was over twice that of Germany in the second half of 1940).

By late August/early September the Luftwaffe believed Fighter Command was all but defeated and expanded its attacks to industrial targets including London (probably by mistake initially), a move sometimes seen as the turning point of the Battle, but though Hugh Dowding (AOC Fighter Command) was concerned about his forces going downhill, Luftwaffe squadrons were in as bad, if not worse, shape. Various "what if" scenarios could be constructed for a more focused German attack, or less efficient RAF defence, but as fought it was a battle of attrition that the Luftwaffe were never winning.

Stephen Bungay's Most Dangerous Enemy is an excellent book on the Battle, as is James Holland's The Battle of Britain and Richard Overy's The Battle of Britain: Myth and Reality. There's also [a lengthy thread from a couple of years back here] (https://www.reddit.com/r/AskHistorians/comments/2pompb/fact_or_fiction_hitler_almost_destroyed_raf_by/) with a fine answer from /u/Domini_canes, and [a slightly more recent thread] (https://www.reddit.com/r/AskHistorians/comments/5gkybt/what_are_people_talking_about_when_they_say_the/) I chipped in to.

The short answer is that the RAF were more than a match for the Luftwaffe and that while their destruction was a possibility, the Luftwaffe was nowhere close to accomplishing that and it would have certainly not been an easy task. Technical specifications of planes and skill of pilots are also not a major factor as they were on average on par with each other, it was the strategic differences that really changed things.

An answer I wrote some time ago about the Luftwaffe strategy and RAF strength during the Battle of Britain covers your question in depth.

The Battle of Britain was a loss due to the sheer lack of competence on the Luftwaffe's part more than it was necessarily won by the effectiveness of the RAF.

The Luftwaffe was vastly more powerful than the RAF was. The Luftwaffe deployed 3,358 aircraft against the UK (2,550 of which were serviceable). In comparison, the RAF had 1,963 serviceable aircraft.

There were times where it did seem that the Luftwaffe were overwhelming the RAF, like when they bombed radar systems at various airfields (and took them off air for a few hours) but they never kept to that strategy, because of the Blitz.

German bombers once mistook the city of London for a military target, and in return the RAF bombed Berlin. This began what was known as the Blitz, as the precedent of the Battle of Britain became to bomb civilian targets, mainly to break morale.

Daylight raids began in September attacking industrial and civilian targets in places like London, Coventry and Clydebank, and at this point attacks on strategic targets like airfields soon ceased. This largely spared the RAF large losses and allowed them to recuperate to a great extent. On the other hand, the Luftwaffe had serious losses, 60 aircraft versus the RAF's 26 losses - in just one day, the climax, on September 15.

Crucially, I don't think you can separate the mistakes of the Luftwaffe for the power of the RAF, because they go hand in hand. Germany's intelligence was terrible, and they did not realise the power of the RAF i.e. the Dowding radar system, and ultimately lead to Germany's withdrawal from the skies over Britain.