Isn't this from a song?
Anyway, the first one, I believe, is suggesting that you keep a sense of perspective. When you, one person, stand beside the great, vast, huge ocean, you should realize that you're not that big. It's to keep you from feeling too self-important. You may be important in your company or in your town, but compared with the entire world, you're small.
For the second, you could think the same thing ("the heavens" is another way to say "the sky") or it could be a suggestion to remember the appreciate the beauty in nature. A "passing glance" is just a quick look. Take the time to look at, and appreciate the beauty of the world.
Someone else may have another interpretation for the second one, or even both of them, but that's my understanding.