12 teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly in the present age,
In verse 12 grace teaches something negative and something positive. It teaches two negative things and three positive things.
First let us look at what grace teaches us negatively.
12 teaching us
Grace teaches something. It not only saves our soul but it undertakes our training in time. “Teaching” means instruct, educate, carrying the idea of nurture. We get our word pedagogy from this Greek word. Grace is our tutor; it nurtures our Christian lives.
The result of teaching by discipline or nurture is that we will do something negative and something positive. A battery needs both a negative and a positive pole; otherwise, it will not start a car. We need both negative and positive in the Christian life. Some people never get beyond the negative in their Christian life.
denying [renounce] ungodliness
The Greek for “denying” indicates that we are to deny decisively. Deny means to repudiate. The Christian must willfully reject anything that is not godly.
Grace teaches us to deny ungodliness. Ungodliness is the lack of respect or reverence for God. This person lives as if God does not exist.
and [the] worldly lusts,
Grace teaches us to deny worldly lusts. We are to refuse all worldly lusts—the “the” indicates that we leave out everything that relates to worldly lusts. A “worldly” lust relates to Satan’s cosmic system of belief. It is any belief opposed to God. It is a world order run by the prince of the world alienated from God (Eph 2:2). The entire system is alien to God (1 Jn 2:15-19).
The grace of God teaches us to say “no” to some things.
There is a renunciation aspect to Christianity. Lusts come from the source of the satanic world system. They originate from pride, status, power, and greed. These lusts are inordinate longing for material possessions, vanity, pleasure, and power.
Refusal to take part in the pleasure of sin must be clear cut. We repudiate the delight temptations offer. We tear them up by the root from our soul. Otherwise, they will put a pock on our spirit; Satan will put his stamp and trademark on us. Christians march to a different drumbeat than this world system. We are different for having been washed by the blood of Christ.