A thought is harmless unless we believe it.
It’s not our thoughts, but our attachment to our thoughts, that causes suffering.
Attaching to a thought means believing that it’s true, without inquiring.
A belief is a thought that we’ve been attaching to, often for years.
Byron Katie
Mindfulbalance 
This is huge, sometimes I think thoughts are like social media. You’d be crazy to believe everything you see on there is true!
Hi Brenton, This is very true. Buddhism argues that information comes into us through six senses – sight, smell, taste, hearing, touch and thinking. We practice developing Awareness so we can be observe our thoughts without getting hooked by them. Karl