We live with the end in mind, but two sub-points must be made.
First, the biblical vocabulary for this eschatological authenticity is the term second nature. Our original nature has been misshapen by sin. When we invite Christ into our lives and cooperate with his spirit to change, our old nature is killed off and our new nature is cultivated.
Anyone who belongs to Christ has become a new person. The old life is gone; a new life has begun!
-2 Corinthians 5.17
Paul refers to this process as being akin to putting on clothes of righteousness (Galatians 3.27). Clothes must be put on. Clothing requires our involvement. Your pants don’t show up on your legs by accident.
Cultivating the second nature requires your participation.
Secondly, following Jesus will make you authentic. We must do good even before we are inwardly motivated, trusting that the process of obedience and cooperation with the spirit will eventually change our hearts and supply the motivation we currently lack. The discipline of being the person God wants you to be will form you into the person God has destined you to become.
The New Testament has several lists of virtues and vices that are helpful in cultivating the second nature. They are given to us so we have a concrete picture of life lived the way God intends.
Ephesians 4.25-5.2:
So stop telling lies. Let us tell our neighbors the truth, for we are all parts of the same body. And ‘don’t sin by letting anger control you.’ Don’t let the sun go down while you are still angry, for anger gives a foothold to the devil. If you are a thief, quit stealing. Instead, use your hands for good hard work, and then give generously to others in need. Don’t use foul or abusive language. Let everything you say be good and helpful, so that your words will be an encouragement to those who hear them. And do not bring sorrow to God’s Holy Spirit by the way you live. Remember, he has identified you as his own, guaranteeing that you will be saved on the day of redemption. Get rid of all bitterness, rage, anger, harsh words, and slander, as well as all types of evil behavior. Instead, be kind to each other, tenderhearted, forgiving one another, just as God through Christ has forgiven you. Imitate God, therefore, in everything you do, because you are his dear children. Live a life filled with love, following the example of Christ. He loved us and offered himself as a sacrifice for us, a pleasing aroma to God.
Ephesians 5.3-5:
Let there be no sexual immorality, impurity, or greed among you. Such sins have no place among God’s people. Obscene stories, foolish talk, and coarse jokes—these are not for you. Instead, let there be thankfulness to God. You can be sure that no immoral, impure, or greedy person will inherit the Kingdom of Christ and of God. For a greedy person is an idolater, worshiping the things of this world.
Ephesians 5.16-20:
Make the most of every opportunity in these evil days. Don’t act thoughtlessly, but understand what the Lord wants you to do. Don’t be drunk with wine, because that will ruin your life. Instead, be filled with the Holy Spirit, singing psalms and hymns and spiritual songs among yourselves, and making music to the Lord in your hearts. And give thanks for everything to God the Father in the name of our Lord Jesus Christ.
These lists are in no way exhaustive. They serve simply as guidelines. At the very least, we know that our future selves, united with God in heaven, will never do these things, so we ought never to do them now.
The basest entry point for eschatological authenticity is avoiding sin and cultivating virtue. We must not be shy in talking about sin. Sin, properly understood, is the force of anti-creation. Sin makes life worse. God wants to make life better, to make all things new, and to remake the world.
No longer will babies die when only a few days old. No longer will adults die before they have lived a full life. No longer will people be considered old at one hundred!
-Isaiah 65.20
If we fail to take sin seriously, the forces of anti-creation lead us away from God’s promised future. This is why people who will not deal with their sin will never get closer to God. Sin must be carved out of us. Sin must be put to death, so the life of God has room to grow in us.
Every day, in every exchange, we must make the decision whether or not we are going to be people who ruin heaven or people who say, “Yes, Lord. Thy kingdom come, thy will be done, on earth as it is in heaven.”
And that gives God glory.