Self-control (ἐγκράτεια) means to have strength over one’s appetites through regulating emotions, thoughts, and behaviors in the face of impulses or temptations.
Self-control is an aspect of the fruit of the Spirit, Galatians 5:23. Since it is a part of the fruit belonging to the Spirit, we cannot obtain it through law or self-effort. Those who seek to be righteous through their works, although having a word of wisdom through self-imposed religion, humility, and the neglecting of the body, do not through these enjoy freedom over the indulgences of the flesh, Colossians 2:23. Self-control is a product of walking by the Spirit; therefore, self-control is an ingredient of the characteristics of Christians who are Spiritual, Acts 24:25.
As we work out our faith, we gain knowledge. To this knowledge, we are to add self-control, through which we can apply godliness to our lives, 2 Peter 1:6. As we continue to mature, we add to godliness a fondness for the brethren that gives place to seeking the best for the ones loved, so the we abound and are not unfruitful or barren in the full experiential knowledge of Jesus Christ our Lord.
Therefore, self-control is a natural result of seeking out and governing our lives by the desires from the Holy Spirit, so that in freedom we maintain strength over our appetites, emotions, thoughts, and behavior in a worthy manner that glorifies God as the Holy Spirit produces the character of Christ through us.