I would encourage you to put your question about, “Why didn’t God just make a world without the ‘ability’ for us to do evil in the first place?” in Bible Questions for a more complete discussion. (There may already be a post for it!)
I think one of the things to keep in mind is that sin is the cause for separation between God and man and is why Jesus came to make our salvation possible. Sin cannot dwell in the Presence of God, otherwise Jesus could have skipped a trip here because there would be no need for justice. His perfected place for us to dwell does not have to take away our access to free will.
And sin has already been overcome!
God made him who had no sin to be sin for us, so that in him we might become the righteousness of God. 2 Corinthians 5:21
God’s perfection and holiness repels all sin/evil. When we reach heaven we will have received our new, imperishable, immortal bodies, and all things are made new and perfected.
So will it be with the resurrection of the dead. The body that is sown is perishable, it is raised imperishable; it is sown in dishonor, it is raised in glory; it is sown in weakness, it is raised in power; it is sown a natural body, it is raised a spiritual body.
If there is a natural body, there is also a spiritual body. So it is written: “The first man Adam became a living being”; the last Adam, a life-giving spirit. The spiritual did not come first, but the natural, and after that the spiritual. The first man was of the dust of the earth; the second man is of heaven. As was the earthly man, so are those who are of the earth; and as is the heavenly man, so also are those who are of heaven. And just as we have borne the image of the earthly man, so shall we bear the image of the heavenly man.
I declare to you, brothers and sisters, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. Listen, I tell you a mystery: We will not all sleep, but we will all be changed— in a flash, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed. For the perishable must clothe itself with the imperishable, and the mortal with immortality. 1 Corinthians 15:42-53 (emphasis mine)
But in keeping with his promise we are looking forward to a new heaven and a new earth, where righteousness dwells. 2 Peter 3:13
Believers have been clothed in the righteousness of Christ in this life which renders us worthy in God’s eyes to come into His Presence.
I delight greatly in the Lord;
my soul rejoices in my God.
For he has clothed me with garments of salvation
and arrayed me in a robe of his righteousness, Isaiah 61:10
In this new life we become what we are meant to be which is perfected and sinless.
No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him. 1 John 3:6
As we begin to live in His fully revealed Presence, scripture tells us of the perfected state of our eternity which would require the eradication of sin. The imperfect will not dwell with the perfected. The current state of things will be no more.
And I heard a loud voice from the throne saying, “Look! God’s dwelling place is now among the people, and he will dwell with them. They will be his people, and God himself will be with them and be their God. ‘He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away.”
He who was seated on the throne said, “I am making everything new!” Then he said, “Write this down, for these words are trustworthy and true.”
He said to me: “It is done. I am the Alpha and the Omega, the Beginning and the End. To the thirsty I will give water without cost from the spring of the water of life. Those who are victorious will inherit all this, and I will be their God and they will be my children. Revelation 21:3-7