It has nothing to do with “Δὀξα τω Θεώ".
Χαρά means joy. Θεός means God. Χαρά Θεού is a very common phrase in Greek and has an idiomatic meaning.
When it refers to a person it means “very happy, full of joy”. For example “Αυτός ο άνθρωπος είναι χαρά Θεού”, ie he is full of joy.
When it refers to other things or situations, it means “very pleasant, very nice”. For example “Έξω είναι χαρά Θεού, εσύ γιατί κάθεσαι μέσα;”, ie “it is such a beautiful weather outside, why are you staying inside?”.