I think yes,certainly Ukraine must and should be in the EU, because Ukraine is a Christian country and the EU is a Christian club,apart from being a European country,no more to say.
I do not think it will come a day when we see a non-Christian country in the EU,in the issue of turkey, it's just a waste of time for the EU as for turkey (I think logical),turkey should think about building a Muslim club union with the countries of the Middle East/asian including Azerbeijan etc...,like us in the Maghreb Union.
A weak country in the Muslim population as albania or kosovo,bosnia,maybe they become EU members (easier to control),but like turkey,Morocco,never,I know very well what is the EU.