If I had the attention of the whole world, and they really were listening to me for two minutes, I would only have to say 9 things:

Love more,
forgive more,
understand more,
share more.
Fight less,
hate less,
judge less,
want less,
compete less.

If we all changed our attitudes towards other people with those 9 things in mind then the world would instantly become more harmonious and people would enjoy better quality lives.