How should Christians act towards non-Christians?

One example I have found is 2 Corinthians 6:14 [KJV].

> Be ye not unequally yoked together with unbelievers: for what
> fellowship hath righteousness with unrighteousness? and what communion
> hath light with darkness?

I believe this is saying not to marry non-Christians.

Are there any other instructions on how to behave towards non-Christians in the Bible?