Jim West came down, seemingly jokingly, against New Year Resolutions with a quote from James 4:13-16.
13 ¶ Ἄγε νῦν οἱ λέγοντες· σήμερον ἢ αὔριον πορευσόμεθα εἰς τήνδε τὴν πόλιν καὶ ποιήσομεν ἐκεῖ ἐνιαυτὸν καὶ ἐμπορευσόμεθα καὶ κερδήσομεν·
14 οἵτινες οὐκ ἐπίστασθε τὸ τῆς αὔριον ποία ἡ ζωὴ ὑμῶν· ἀτμὶς γάρ ἐστε ἡ πρὸς ὀλίγον φαινομένη, ἔπειτα καὶ ἀφανιζομένη.
15 ἀντὶ τοῦ λέγειν ὑμᾶς· ἐὰν ὁ κύριος θελήσῃ καὶ ζήσομεν καὶ ποιήσομεν τοῦτο ἢ ἐκεῖνο.
16 νῦν δὲ καυχᾶσθε ἐν ταῖς ἀλαζονείαις ὑμῶν· πᾶσα καύχησις τοιαύτη πονηρά ἐστιν. (James 4:13-16 BGT)
Come now, you who constantly say, “Today or tomorrow we will go into this city and we will stay there a year and we will do business and we will make profit; you cannot know that which happens tomorrow. What is your life? You are a vapor, appearing for a brief time, then dissipating. Instead, you should say, “Should the Lord will it, we both will live and do this or that. But as it stands, you are boasting in your arrogance, all such boasting is from the Evil One.” (James 4:13-16)
Now, this being the case, planning ahead seems like an awful idea. But there is more to James’ story:
17 εἰδότι οὖν καλὸν ποιεῖν καὶ μὴ ποιοῦντι, ἁμαρτία αὐτῷ ἐστιν. (Jam 4:17 BGT)
Which translates, “Therefore, whoever knows the good he ought to do and does not do it, to him, it is sin. (James 4:17)
It seems, rather, that planning ahead to do good is the idea (ie to do what the Lord should will), rather than planning ahead to do what ever you want. Even better stated, plan ahead to do good and not to do evil. In this sense a New Year’s resolution is like an adiaphora cultural practice than can be used to help you do good. I think James, like Paul, is concerned about human boasting. Good works and future plans should not be for boasting and self-aggrandizement, but for the good (or more theologically: for God’s glory).
Jonathan Edwards’ journals are filled with resolutions to do good as is his list of resolutions.
Anyhow, other Scripture speaks of this same issue. For instance, right after Paul tells his compatriots that there is not room for boasting in Ephesians 2:8-9, he says:
10 αὐτοῦ γάρ ἐσμεν ποίημα, κτισθέντες ἐν Χριστῷ Ἰησοῦ ἐπὶ ἔργοις ἀγαθοῖς οἷς προητοίμασεν ὁ θεὸς, ἵνα ἐν αὐτοῖς περιπατήσωμεν. (Eph 2:10 BGT)
For we are his project, created in Christ Jesus for good works which God prepared in advance so that we should walk in them. (Ephesians 2:10)
God has prepared good works to be done, thus Christians should do them (without boasting). But later in Ephesians Paul talks about being “renewed in the spirit of your mind, putting on the new man according to God, the creator, in righteousness and the piety of truth (Ephesians 4:23-24).” This kind of life takes forethought, like resolving, according to God’s will to memorize chunks of Jesus’ teaching, making plans to visit the sick in hospitals, and resolving (planning in advance) to have vacation times on weekdays rather than miss church services, etc.
In this respect, even self-improvement resolutions would be a good thing as long as it was self-improvement which did not contradict the example of John the Baptist (he must increase, I must decrease). The rule in terms of what ways to engage in self-improvement is also Scriptural, “test everything carefully, hold fast to that which is good (1 Thessalonians 5:21).”*
*Note: Paul’s teaching in 1 Thessalonians is about teachings from supposed prophets and thus about ideas in sermons in particular, and therefore applicable to ideas in general. If an idea is good, true, and beautiful and then also able to be put into practice without damaging your calling in life, then you not only can plan to do it. You probably should.