It will all work out fine, cause good intentions and idealism just force reality into pleasant shapes.. but then again, it is those who want it to work out fine, who constantly highlight group differences, preventing the melting pot from working. Its good that these places exist, merging the people into one meta-group identity (Menschen in Deutschland), its bad that people like you try to with the best intentions sabotage things by sweeping problems under the rug.

https://en.wikipedia.org/wiki/Lebanese_Civil_War https://en.wikipedia.org/wiki/Yugoslav_Wars https://en.wikipedia.org/wiki/Syrian_civil_war