Idiom meaning "One should not despair ..."

I wonder whether there are any idiom(s) meaning "While you know that your ultimate goal is impossible to achieve completely, you should try your best to at least get a glimpse of it because it's enormously valuable".

The nearest things I can imagine are "Getting a glimpse of your goal is better than nothing" and "Half a loaf is better than None".

Shoot for the moon - even if you miss, you'll land among the stars.

This phrase suggests that even a very difficult task can be worth undertaking, as even failure may bring some benefit. The ultimate goal might not be achievable, but trying to achieve it is still worthwhile.

It is better to light a single candle than to curse the darkness.

The meaning is that it is better to do what you can, no matter how little it may seem, than not do anything and just give up.

The earliest known use is in a sermon of W.L. Watkinson, in 1907.