I believe God doesn't really have a word in japanese, seeing most of them are buddhist, so the word 'god' is related to god of river, god of mountain, etc.
You are god
anata wa kami desu
あなた わ かみ です
You are my god
anata wa watashi no kami desu
あなた わ わたし の かみ です
I will miss you
My japanese hasn't got as far as the word 'miss'
Also, I haven't learnt any kanji, hence I only wrote the hiragana for the translation...
This is my attempt at translating those words, though you might want to wait for other posts to confirm the translation, since I'm rather new at this language
Don't ask me anything about German. The only word I know is 'doppleganger'

(I might even mispell the word
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)