I agree that there is definitely a spiritual aspect, but I had thought of this great song more as a break-up song. The singer's girlfriend was never that good to him, and he has realized that it is alright to move on. He has been wasting time in a life that has not been fulfilling, and was blind believing that everything was alright. He opens up his eyes and sees that it's his time to move on. He says goodbye, and then focuses on seizing the day, which is what all of the "today" metaphors are about.
I agree that there is definitely a spiritual aspect, but I had thought of this great song more as a break-up song. The singer's girlfriend was never that good to him, and he has realized that it is alright to move on. He has been wasting time in a life that has not been fulfilling, and was blind believing that everything was alright. He opens up his eyes and sees that it's his time to move on. He says goodbye, and then focuses on seizing the day, which is what all of the "today" metaphors are about.