I posted
this article the last time this topic came up, but it's a good enough read that I have no difficulty posting it again.
The crux of the matter, to me, is summed up early on in the piece:
and, regarding the Free Will defence:
The idea that some are condemned to an eternity in hell seems incompatible with the belief in a a God who loves all.
My Lutheran pastor has implied that everyone will go to heaven. He said that salvation comes through undeserved grace, and that not even believing in the wrong religion can keep a person from receiving that grace.
Jesus died for everyone's sins, didn't he?
That's not the issue though.
The problem isn't about God's grace, it's that Jesus himself said some things that are really hard to reconcile with universalism. I'm thinking of Matthew 25:31-46 in particular (the sheep and the goats). It's really hard (I'd say impossible) to square that passage with universalism.
The problem with scripture is that the gospels were not written in english
What is clear is that in the early days of the church plenty of greek speakers (which, after all is what the gospels were written in) like Origen and Gregory of Nyssa and so on, interpreted Matthew 25:46 as meaning for "a long time" But anyway, if you wish you can easily find seemingly universalist verses in the New Testament in english, like 1 Corinithians 3 10-15. This isn't an issue where scripture is unambiguous.