I owed you a comment from months back, and now I've finally got off my lazy butt to do it :D I do like this poem, it is a good read, so here we go...:

Sitting on top of a hill,
Watching the world beneath,
Knowing any day now
It could shatter
Right beneath my feet.

^^I like the imagery here, but I think it could have more, 'poetic'. More like 'show', not 'tell'. Also, and this applies to the rest of the poem, if you added punctuation it could give the reader a better flow of the poem. I've added in the punctuation for you, you can use it if you wish :)

When the wind blows
Through your hair,
And the old man sings,
You know you'll have life
And you'll grin and grin,
Like there's no such thing
As sin.

^^ I like the 'knowing you'll have life', seems quite original and unique, gives the poem a feel-good aspect. I'm not too sure about the 'grinning', it isn't strong enough to get the message across. Also, if you are going to have a rhyme scheme (even a loose one) you need to stick to it, otherwise it can distract the reader. But apart from that, I like the ideas happening here, nice stanza :)

Everything in life
(Not including strife)
Makes me laugh
Like there's no tomorrow.

^^ The second line sounds forced here, as it tries to fit into your rhyme scheme. I say leave the rhyme alone here and put in something more meaninful. The 'laughing like no tomorrow' is nice, again continuing the feel-good theme. Also the stanza length is becoming erratic, so it either needs to be stricter with a good rhyme scheme, or you could abandon the rhyme scheme completely in favour of free verse (which I would suggest here, too many seperate ideas for a strict scheme). But apart from that, I like the theme here, nice work :)

But whenever the world
Suddenly becomes dark,
And I can no longer see,
I'll try to shine brightly.
My small bright star.
And the world will see,
What I could always be.

^^ And here we get the 'glow' that represents the title. However, this has moved on if you compare it to the beginning. Maybe, at the beginning, you could already be a star shining onto Earth, then you could glow brighter when the world is dark. just a thought :) You've repeated see, possibly for the rhyme scheme, but I would change that to something more 'poetic'. But I do like the idea here :)

Overall, you have a very nice idea here with some great concepts and images. To improve, I would:

1. Add punctuation. It allows the reader to pause in the right places, as sometimes these pauses aren't obvious.

2. Ditch the rhyme scheme. This poem, in my opinion, is quite unique, so I think you should allow it to be itself and get rid of the rhyme scheme. Rhyme schemes are best on challenging poets to take thier own light on common topics, like love or nature. Plus, I didn't really notice the rhyme scheme for a little while, as it is rather sparse.

3. Show, not tell. You have some wonderful ideas here, and if you added some more imagery, it could really bring out those ideas. For example, instead of saying 'My small, bright, star' you could say something like. A tiny point of hope, furiously striving to make a differnce with her rays of innocence. I know it's longer and doesn't rhyme well, which is why I'm saying ditch the rhyme scheme.

You don't have to change the poem at all if you are happy with it, I just think it is a shame for such a lovely idea to go unnoticed. Take the tips I've given you and see if you can incorporate it into some new poems you write.

I'll give this piece a 4/5 for now, and I'm sorry I've rambled on for a while :)

Keep writing, and well done,
Emily :)