it’s not possible to know anything you can’t conceive of, God in the Judeo/Christian sense is beyond human conception, so you can’t know God. You can only know aspects of God, i.e. that God is love, compassion or forgiveness.
God is subjectively the highest, most noble and pure ‘good,’ that you can imagine. Your conception of God is limited by your imagination. This makes God your own personal standard of absolute goodness, as there is none better than God. We are all various degrees of separation away from absolute Goodness, not because we’re evil, but simply because we cannot imagine what it is to be totally good.
The road to hell is littered with good intentions.
Also what is good for you, may not be good for another. Different ideas of ‘good,’ can often clash which is why philosophers spend so much time studying goodness or virtue, we have to collectively agree that which is good so as to avoid future conflicts, after all within the space of his own mind, Hitler thought himself to be ‘good,’ as did Saddam Hussein and a whole host of dictators, tyrants, murderers and enslavers of men throughout history, hence the study of virtue was of profound importance to the great thinkers of the ancient world and is still relevant today.
So what is the most sublime good?
In a word Love.
“Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It does not dishonour others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, always perseveres.”
Saul of Tarsus, 1 Corinthians 13 – 4-7
Dear friends, let us love one another, for love comes from God. Everyone who loves has been born of God and knows God. Whoever does not love does not know God, because God is love.
1 John 4-7
No one has ever seen God; but if we love one another, God lives in us and his love is made complete in us.
1 John: 4 – 12