Romans 1:20 For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse.But we know that God is a just and fair God. He will not violate a person's right to exist (since they are created in the image of God) thus, the choices a person makes in this life will be be validated for eternity. The stern warning of Jesus Christ to the world was that unless a person repents, they will "perish" for eternity (Lk. 13:1ff). Rather than obstinately telling God that this is "unfair", we should instead be thanking God that He has made it possible for any one of us to be forgiven of our sin and to be adopted into His family as a joint-heir with Christ!
John 17:3 And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent.This is the God we are coming to know. A God who has revealed himself in the Book of nature and the Sacred Book of Scripture. It is this God who sent His eternal Son to the world to reveal to us the most complete image of God we will have in this lifetime. Once a person experiences this God through revelation (Eph. 1:18), prayerful communion, a community of grace, and the living Word of God they can confidently say that they know who God is.
Father, we want to know you more. Help us to know you. Help us to make you known. Teach us Your ways and give us the grace to follow You.