If you mean a harmonious life, when we are all brothers and sisters, then many people already live like this. Every religion has seeds of truth. Those who come to this understand that God is one for all religions, that this is Love in different manifestations. About different peoples - yes, we are all different, no one argues with this, but it's great that we are all so different! We all just need to start with our own development, start acting according to our conscience in every moment, and then everything will be fine.
The truth is that false religions are in the hand of the satan, a malevolent entity who controls the Matrix.
True Religion draws you close to a CREATOR whose Holiness and Purity is indescribable and won't allow you to do evil. His Holy Spirit dwell in truly religious people and helps them do good always. Anyone without the Spirit doesn't belong to the CREATOR and can't do what's right. What lives in that person is actually darkenness - evil spirit.
It's hard to be evil or live in sin while being in the CREATOR's presence. No evil can stand or survive HIS absolutely brilliant Presence. Anyone who is truly religious will be good always.
Satan uses false religions to make the true religion look bad.
You will know the truly religious ones by the fruits they produce. They will produce good fruits alway. A good tree cannot produce evil fruits. A bad tree cannot produce good fruits. So,you shall know them by fruit... it's as simple as that.