my mother and I got into a debate about this sentence because grammtically correct?

[Lindsey]

Is this sentence correct? It was on a church sign. The sentence read: "Holy is the Lord, who was and is to come again."

 

[Mizu]

In a purely grammatical sense it would be incorrect, but as it is using more of a biblical "dialect," I think it would be correct in that sense.

 

[Bride of Squidward]

Who was and is and is to come - would be correct.

 

[charcinders]

It is grammatically correct, if a bit florid.

The "was" implies that the Lord was, but isn't any more, i.e. he doesn't exist at the moment, which is probably not what they wanted to say!
"who was among us and is to come again" would make more sense.

 

[Keyring]

"Who was and will come again" makes much more sense. That sentence implies that he "was to come again", which makes no sense.

 

[Across the River Bend]

It isn't necessarily grammatically incorrect though, since (I assume) it's a Biblical quote and there's definite poetic license there and sentences are structured differently.