Naming a kid a god's name is a no-go, I'm telling you. Just giving them the name means they're already outclassed by it.
Literal
God-[honorific-様] [attributive-の] name [topic-は] as-expected NG [quotative-だと] think-[assertive-よ](elongated-~). Already named [at-the-point-of-時点で] name-defeat is-[nominalizer-な][explanation-わけ][isn't-it-じゃん].
Casual baby-name chat. ＮＧ is a loanword acronym ('no good, not allowed') — originally from film/TV slang for a bad take, now general-purpose 'no-go.' 名前負け is a fixed term meaning 'to be outdone by one's own name' — when a name is too grand for the person bearing it. ~わけじゃん is casual for ~わけじゃない (rhetorical question: 'isn't it the case that...?'). じゃん is the Kanto casual sentence-ender for 'isn't it, right?' The ~ at the end elongates the vowel of よ for casual drawn-out speech.