Breaking through into the Divinity Realm could be considered hard and easy at the same time. Hard because the amount of energy needed was enormous, but especially because, even with the necessary Divine origin Energy, there was a high chance of failure to push past the barrier.
As for why it was also easy? Because the requirements had been fulfilled the moment you reached the Peak of the Space-Time Realm. The Divinity Realm required you to merge the Sub-laws into the Major Law. But that would only start once you were already in the Divinity Realm. Simply put, there were no changes to be made when going from the Space-Time Realm to the Divinity Realm. It was all about energy and nothing else.