Answer: God is "appealing" to everyone THROUGH Christ Jesus. God appeals to, or calls out to, everyone to be reconciled to HIM, (verse 20). God has revealed this Way of reconciliation to Him THROUGH His Son. God offers the Way, Which is Christ, through the Truth, Which is Christ, to obtain Life, Which is Christ. AND there is only ONE Way through the ONE Truth to obtain the ONE Life that brings us back to God. Everyone MUST believe in and be obedient to God's Son, Jesus Christ our Lord. Jesus had no sin, but God made Jesus to BE sin FOR US. Why? So that IN Jesus we might become the righteousness of God, (verse 21).
MORE INFORMATION AND/OR OTHER SCRIPTURE REFERENCES:
We can receive the righteousness of Jesus and thereby stand acceptable--reconciled and justified--before God. This is what God wants for ALL people. But this reconciliation requires that we must humble ourselves, admit our wrongs done to God and accept HIS plan of reconciliation. THIS is the APPEAL God is making to EVERYONE!
Psalm 51:17: "The sacrifices of God are a broken spirit; a broken and contrite heart, O God, You will not despise."
Isaiah 67:15: "For this is what the high and lofty One says--He Who lives forever, Whose Name is holy: ‘I live in a high and holy place, but also with him who is contrite and lowly in spirit, to revive the spirit of the lowly and to revive the heart of the contrite.'"
Matthew 11:28: [Jesus said,] "Come to Me, all you who are weary and burdened, and I will give you rest. Take My yoke upon you and learn from Me, for I am gentle and humble in heart, and you will find rest for your souls. For My yoke is easy and My burden is light."
James 4:4-9: "You adulterous people, don't you know that friendship with the world is hatred toward God? Anyone who chooses to be a friend of the world becomes an enemy of God. Or do you think Scripture says without reason that the spirit He caused to live in us envies intensely? But He gives us more grace. That is why Scripture says: ‘God opposes the proud but gives grace to the humble.' Submit yourselves, then, to God. Resist the devil, and he will flee from you. Come near to God and He will come near to you. Wash your hands, you sinners, and purify your hearts, you double-minded. Grieve, mourn and wail. Change your laughter to mourning and your joy to gloom. Humble yourselves before the Lord, and He will lift you up."
1 John 3:1-6: "How great is the love the Father has lavished on us, that we should be called children of God! And that is what we are! The reason the world does not know us is that it did not know Him. Dear friends, now we are children of God, and what we will be has not yet been made known. But we know that when He appears, we shall be like Him, for we shall see Him as He is. Everyone who has this hope in Him purifies himself, just as He is pure. Everyone who sins breaks the law; in fact, sin is lawlessness. But you know that He appeared so that He might take away our sins. And in Him is no sin. No one who lives in Him keeps on sinning. No one who continues to sin has either seen Him or known Him."
1 John 5:1-5: "Everyone who believes that Jesus is the Christ is born of God, and everyone who loves the father loves his child as well. This is how we know that we love the children of God: by loving God and carrying out His commands. This is love for God: to obey His commands. And His commands are not burdensome, for everyone born of God overcomes the world. This is the victory that has overcome the world, even our faith. Who is it that overcomes the world? ONLY HE WHO BELIEVES THAT JESUS IS THE SON OF GOD."