The opening Test of the Ashes series on Thursday also marks the start of the Test Championship which includes nine participants who will play six series each over the next two years before the final in June 2021.
The competition, organized by the International Cricket Council, is aimed at elevating the popularity of the conventional five-day format that has fallen out of favour with audiences with the influx of T20 cricket.
England recently survived a major scare against Ireland at Lord's following a first-innings collapse that saw them being bundled out for 85 before a supreme new-ball bowling effort from Stuart Broad and Chris Woakes led them to a thumping 143-run victory.
England, currently placed at number four in the Test rankings, are now fancying their chances of winning the inaugural edition of the World Test Championship, according to Giles.
"We've had a focus on the white ball for the last four years and perhaps the time has come to redress that balance," Giles, director of England cricket, told Sky Sports News.
"It was important that the pendulum didn't swing back to 50-50, it had to swing right back to white-ball cricket, which we'd never done in this country.
"Perhaps that (affected the Test team) but we needed to do it if we were serious about winning the 2019 World Cup, which we've done."
Giles spoke positively about the possible impact of the Test Championship and predicted this would help revive interest in the game elsewhere.
"I'm a fan. Test cricket has obviously been marginalised in some parts of the world with the pressure of the shorter forms and the popularity of white-ball cricket.
"This country doesn't really struggle with that. Test cricket remains popular and the Ashes is sold out this year. England versus Australia doesn't need any more promotion but around the world it's not that easy."
Former Australian skipper Steve Waugh noted that the championship will provide a sense of fulfillment to the top-performing side by attaining a prized trophy.
"It is great for Test match cricket. I played a lot over 18 years and many people said we were the number one Test side in the world," he said.
"But unless you hold up a trophy or get to that final match you're not really sure. I think Test cricket really needs this. You need something to hang your hat on if you are the best Test team in the world."