We are more than a week into 2020 and if you made any resolutions my guess is you have already broken them at least once by now. I quit making resolutions a long time ago. Not that they are a bad thing, it is just that I am really bad at keeping them.
The end of the year and the beginning of the next is the time where we get very introspective and decide that we are going to work on ourselves. Which is a great idea if you need to lose weight, be a better mom or dad, or make more money. Those are all good things. Good things from a horizontal perspective but where things convoluted is when we begin to think that "bettering ourselves" adds anything to our account vertically; that is in our relationship with Christ.
Here we get to the two kinds of righteousness, something Luther really develops in his commentary on Galatians. There are two kinds of righteousness: one that comes to us as a gift from outside of us in Christ and another that comes to us by virtue of the law. One that is a finished work that cannot be added to, and another that is continuous and must be developed. One that is passive, and another that is very much active.
Sometimes we (those of us who champion grace and rest in the finished work of Christ) get accused of not caring about the law, or dismissing good works. This kind of accusation is a straw-man argument that does not understand the theology of the cross in the least. It is not that we throw out the law, or good works it is that we do not believe the law or good works can aid in our salvation or holiness.
When we talk about bettering ourselves, we need to realize that a theology of the cross does not militate against this endeavor but that it places it squarely in the horizontal realm. It does not give us more righteousness toward God, and if it's done purely for selfish reasons (only benefiting you) it is not useful at all from a Christian perspective. The only way that bettering ourselves is beneficial is when it benefits our neighbor. Self-betterment in an attempt to earn favor with God is an affront to the finished work of Christ. Self-betterment that only benefits the individual and is not aimed at loving one's neighbor is actually sinful and weakens the importance of vocation as the primary way that Christ is working through us to love and serve humanity.
This is what Paul means in Galatians 5:6 when he talks about "faith working itself out in love." Faith is passive — it delivers Christ to us with all his promises and gifts. Love is active and it delivers to our neighbor what they need. Here our good works are taken out of the vertical realm (something we do for God) and they are placed in the horizontal realm (something we do for our neighbor). Good works, if they are actually good, are not aimed at bettering ourselves (becoming more holy) nor are they aimed toward God they are aimed toward our neighbor. For God doesn't need our good works, but our neighbor does.
As you look ahead toward 2020. Don't let anyone burden you with works you need to do for God. Don't allow all the noise on social media about becoming a "new you" add weight to your already heavy load. If you see areas in your life that need improvement then do whatever it takes to be better, not as an end goal or as a way to leverage favor with God, but as a means to live your life for the good of your neighbor. Who is your neighbor? They are the people right in front of you — your spouse, your children, your co-workers or employees, etc. You do not need to go find these people as they are right in front of you in your daily life. For the Christian life is not about you, nor is it about your maturity, your holiness, or your good works. It is about Christ and what he gives you and does for you.
Our sin nature wants tangible goals to measure how we are doing, so we complicate what should be simple and freeing and turn inwardly toward self-improvement. Christ has given us something very different. You can find "be a better you" anywhere but Christ promises us something we can't find anywhere else. He drowns our old man with all his goals and aspirations and resurrects a new man, clothed in the righteousness of Christ. Then he says, every day when you get out of bed, remember your baptism, remember that your old man (your old Adam and Eve) with all her sin and guilt and shame, with all his striving to be better is really truly dead, and you are alive in me. You are forgiven, it is finished, you are free, you can rest. This is the Christian life, coming back to this truth every single day. It's what Jim Nestingen calls "the drowning and dancing" of the Christian life. The drowning of the old man (this is the work of the law) and the dancing of the new man (the work of the gospel). We dance our way through this life as we recognize that we can't screw this up. You got an A on the exam before you even took it. Therefore the pressure is off which does not mean you should give up trying to improve yourself. It just means that your failure to do so does not define who are.