Jesus, the Son of God, has authority because of his special relationship with his Father. (See: [[rc://en/ta/man/translate/guidelines-sonofgodprinciples]])
The implied information is that Jesus is not alone in his judgment. AT: "I am not alone in how I judge" or "I do not judge alone" (See: [[rc://en/ta/man/translate/figs-explicit]])
The Father and the Son judge together. AT: "the Father also judges with me" or "the Father judges as I do."
# the Father
This is an important title for God. If your language must state whose Father this is, you could say "my Father" since Jesus switches to that in the following verses. (See: [[rc://en/ta/man/translate/guidelines-sonofgodprinciples]])