My love interest is insecure

Hi,

The person I am interested, shows signs of insecurity. He is not hurtful to me but, he puts himself down sometimes and says I’m one of the best things that ever happened to him. I want him to be secure and help him through this, but how do I do it? How can I help him to help himself?

I want him to be happy and secure with himself before we get into a relationship and be happy together.