The trouble with New Year's resolutions is that they attempt to do by human power under the Law what can be done only by the Holy Spirit under the Gospel.
Dietrich Bonhoeffer said:
At the beginning of a new year, many people have nothing better to do than to make a list of bad deeds and resolve from now on -- how many "from-now-ons" have there already been! -- to begin with better intentions, but they are still stuck in the middle of their paganism. They believe that a good intention already means a new beginning: they believe that on their own they can make a new start whenever they want. But that is an evil illusion: only God can make a new beginning with people whenever God pleases, but not people with God. Therefore, people cannot make a new beginning at all; they can only pray for one. Where people are on their own and live by their own devices, there is only the old, the past. Only where God is can there be a new beginning. We cannot command God to grant it; we can only pray to God for it. And we can pray only when we realize that we cannot do anything, that we have reached our limit, that someone else must make that new beginning.
We are dependent on the Holy Spirit, and He works when and where He wills. The Apostle John said,
The wind blows where it wishes, and you hear its sound, but you do not know where it comes from or where it goes. So it is with everyone who is born of the Spirit" (John 3:8)
In accord with the Apostle, the Augsburg Confession says:
The Holy Ghost is given, who works faith; where and when it pleases God, in them that hear the Gospel, to wit, that God, not for our own merits, but for Christ's sake, justifies those who believe that they are received into grace for Christ's sake. (AC, Article V.)
Our reason and strength can do nothing. Only the call of the Holy Spirit can do anything. Martin Luther said:
I believe that I cannot by my own reason or strength believe in Jesus Christ, my Lord, or come to Him; but the Holy Ghost has called me by the Gospel, enlightened me with His gifts, sanctified and kept me in the true faith; even as He calls, gathers, enlightens, and sanctifies the whole Christian Church on earth, and keeps it with Jesus Christ in the one true faith; in which Christian Church He forgives daily and richly all sins to me and all believers, and at the last day will raise up me and all the dead, and will give to me and to all believers in Christ everlasting life. (Martin Luther, Small Catechism, Explanation of the Third Article of the Creed.)
We are dependent on the Holy Spirit, so what we must do is pray for the Holy Spirit. Jesus said,
If you then, who are evil, know how to give good gifts to your children, how much more will the heavenly Father give the Holy Spirit to those who ask him! (Luke 11:13)
Let us pray believing that the Father will give us the Spirit gladly. He desires to give us the Spirit more than we desire to receive him.
Many are so wounded, so defeated by their sins that they hardly dare to pray for the Holy Spirit. They hardly dare to believe. Helplessness does not impede prayer. Helplessness qualifies us to pray. Prayer is for the helpless. Ole Hallesby said:
As far as I can see, prayer has been ordained only for the helpless. It is the last resort of the helpless. Indeed, the very last way out. We try everything before we finally resort to prayer.
This is not only true of us before our conversion. Prayer is our last resort also throughout our whole Christian life. I know very well that we offer many and beautiful prayers, both privately and publicly, without helplessness as the impelling power. But I am not at all positive that this is prayer.
Prayer and helplessness are inseparable. Only those who are helpless can truly pray.
Listen to this, you who are often so helpless that you do not know what to do. At times you do not even know how to pray. Your mind seems full of sin and impurity. Your mind is preoccupied with what the Bible calls the world. God and eternal and holy things seem so distant and foreign to you that you feel that you add sin to sin by desiring to approach God in such a state of mind. Now and then you must ask yourself the question, "Do I really desire to be set free from the lukewarmness of my heart and my worldly life? Is not my Christian life always lukewarm and half-hearted for the simple reason that deep down in my heart I desire it that way?"
The honest souls struggle against the dishonesty of their own being. They feel themselves so helplessly lost that their prayers freeze on their very lips.
Listen, my friend! Your helplessness is your best prayer. It calls from your heart to the heart of God with greater effect than all your uttered pleas. He hears it from the very moment that you are seized with helplessness, and He becomes actively engaged at once in hearing and answering the prayer of your helplessness." (Ole Hallesby, Prayer, pp. 18-19 (Augsburg Publishing House, Minneapolis 1931.)
"Not by might, nor by power, but by my Spirit, says the LORD of hosts." (Zechariah 4:6)
Don't make New Year's resolutions. Pray helplessly for the Holy Spirit, trusting that the Father, for Jesus' sake, will give you the good gift.