Bhagavad Gita, Chapter 10, Verse 14

I regard all this that You say to me as true, O Keshava. Verily, O Bhagavân, neither the Devas nor the Dânavas know Your manifestation.

Full, real acceptance is stated here plainly, with no hedge or partial belief attached.

Arjun's response isn't cautious agreement, it's a direct declaration that everything said is factual. Even beings far more powerful than humans are described as unable to fully grasp what Arjun has just accepted.