Its a general spiritual song about life. Throughout the song, the singer hears (what I presume to be) the voice of God telling him to carry on through hardship and high points. "I was soaring ever higher" perhaps signifies the high points in the singer's life and the following "but I flew too high" may suggest a fall from grace. "Tossed about like a ship on the ocean" suggests being out of control and at the mercy of life's hardships and "I set a course for winds of fortune" could mean the singer's picking himself up out of a down period and moving on to a brighter future. The bridge (and the ending) "Carry on, you will always remember. Carry on, nothing equals the splendor. Now your life's no longer empty. Surely heaven waits for you." suggests that life was worth living through all of the experiences since, if the singer had not 'carried on' then life would have been meaningless.