If Jesus teachings were adopted by the whole of society would the world be a better place?

Very much so. If everyone were to love their "neighbor" (a.k.a. mankind in general) like they do themselves, things would be dramatically different, and for the better. (Matthew 22:39) There will come a time in the future where everyone will conduct themselves in accordance with what Jesus taught. (Isaiah 2:2-3) Jehovah will exercise perfect justice amongst all nations. (Isaiah 2:4) This will occur once Jehovah God's kingdom takes over Earth. (Daniel 2:44)

(New World Translation of the Holy Scriptures)