Did Ancient Israel have open borders? Did they ban usury or not amongst themselves? What about jubilees every 7 years?If both sides can use the Bible to back their beliefs, then there is no peaceful debate/solution. It will always lead to war. Unless you can point out in the bible where free trade, open borders, destruction of the middle class, destruction of the family, all through the means of capitalism is evil, which you can't.
So Christianity alone will not provide any type of cohesion.
Or that fraudulent debt based fractional reserve banking is de facto banned by the law of equal weights and measures:
Which made Capitalism as we know it a total Ponzi Scheme.
Is it not also likewise evil to not provide for one's household?(1 Timothy 5:8). Therefore by extension it's sinful to have no filter for keeping out evil people and mass immigration from foreigners because such a thing is no different from invasion and depriving one's household of their substance by extension.
If Christianity isn't sufficient to provide cohesion. I point you to successful multinational Crusades there had been successful many times.
And helped to unite Europe against the Muslim threat that wouldn't have otherwise haopened with Christianity.