‘This is the message we have heard from him and proclaim to you, that God is light, and in him is no darkness at all.’ (1 John 1:5 ESV)
‘Whoever does not love does not know God, because God is love.’ (1 John 4:8 ESV)
To my knowledge, it is never said that God is justice’ He is said to be merciful, but not said to be mercy. It is similarly never said that God is justice. He is called just, but not justice.
The Holy Spirit did not believe that God should be called mercy or justice. The Holy Spirit believed that God should be called ‘light’ and ‘love.’