What Am I? Riddles

[pdm1]

Any thoughts on the following “What am I?” riddles would be appreciated:

1. I can be the strongest and purest, and you need to think very hard to know who I am.
2. I get lost when you stop believing. I can be broken yet remain whole.
3. My name is short with only 3 letters, but it is what I am and I am what I do.
4. I could be a landlord but have to watch where I land or I could end up behind bars.
5. I have my own but often leave them behind

Thanks for any suggestions.

[mallyh]

5 footsteps?

[Doof45]

2 Heart ?
3 Eye?

[Hazlinny]

5.?? fingerprints

[bhg481]

4 licensee?

[Patsy33]

3 Mum?

[blaris]

1. Diamond? A bit weak I think
4. Monopoly player?

[bhg481]

prefer blaris for 4.

[Zacs-Master]

2. Faith.

[pdm1]

Thanks for all suggestions - some good ones here. Any further ideas for No. 1 would be appreciated.

[barry1010]

Are they all clues to the same thing, or 5 different riddles?

[barry1010]

1. Concentrate

[elliemay1]

Great answer for No.1, barry!

[barry1010]

Thank you, Ellie. I stupidly thought all the clues led to a single answer

[MartinGeorgiev]

Готино като това.

[Patsy33]

Yes, excellent thinking, Barry. :-)