The fight of faith. The battle of belief. This is the war we wage.
Our sanctification, our survival, is tethered to the anchor of our hope. If we are not anchored deep we will be tossed to and fro. We will make shipwreck of our faith.
How do we cast anchor? How do we preserve in life’s storms? How do we wage our warfare?
We do it, the Bible continually shows us, through faith. Yet, how do we have faith? Or how do we increase our faith? We will get to that most practical question. But, first, let’s see (1) where it is that the Bible teaches this and (2) let us understand how faith does do this.
First, the Bible teaches that faith not only saves, but also sanctifies. Our belief that brings us into the fold also keeps us there. This is seen in various places in Scripture, both OT and NT. We’ll take our example from 1 Peter.
God has caused us to be born again through faith (1 Pet. 1:3 cf. Jn. 1:13; 3:3-8; Eph. 2:4-5; Col. 2:13; Titus 3:5; James 1:18; 1 Pet. 1:23; 1 Jn. 2:29; 3:9; 4:7; 5:1, 4, 18); that is, salvation. Yet, faith also continues to work; it sanctifies us, makes us holy in practice. By God’s power we are guarded through faith for salvation (1 Pet. 1:5 cf. Rom. 11:20). We see this worked out in 1 Peter 1. So, taking, for now, just one quick example, Peter says, “Having purified your souls by your obedience to the truth.” We purify our souls because we believe the truth, because we have faith. Faith acts! It did for Peter, it did for Paul (cf. e.g. “the obedience of faith” Rom. 1:5; 16:26), it did for James (James 2:14-26), and it should for us.
Second, how it is that faith sanctifies and preserves us. Again, we will take our example from 1 Peter.
I hate to be repetitive, but here it is. When we believe that we have a reason for hope (1 Pet. 3:15), we know that we are not following cleverly devised myths (2 Pet. 1: 15, 16), then we live accordingly. We, for example, “put away all malice and all deceit and hypocrisy” (1 Pet. 2:1). It’s simply the natural outcome of belief; or, that is, it should be.
So, for example, suppose I am exhausted from a long day’s work. I come home, see that chair in the corner of the kitchen that’s always beckoning me. It’s made from solid hardwood. I got it when I worked at furniture store. I know it’s solid. So, I sit down on it. I rest. I take my boots off.
However, suppose that chair was not made of hardwood. Suppose I did not get it from the furniture store at which I worked. Suppose I got it from a trash heap. I would then have much to question about its sturdiness. If I don’t believe that it will hold my weight then I will not sit in it.
Why? Why do I sit in one chair and not the other? Because I have faith in the one and not the other. Faith, quite literally, moves us. That is why Peter talks about the “tested genuineness of your faith” (1 Pet. 1:7). Faith is testable. Is action wedded with our faith? Do we, so to speak, sit in the chair?
Active faith is seen in various places in Scripture. Thus, it says, “when mindful of God,” i.e. when one has faith, one is willing to endure sorrows (1 Pet. 2:19). We are even told to rejoice when we share in Christ’s sufferings—Christ suffered an agonizing death on a cross—because then we will be blessed (1 Pet. 4:13-14; 5:4, 10). We can only rejoice at such things if we truly have faith.
Third, and practically, how can we be firm in the faith? How can we preserve? How can we increase in faith? This is very important because as Isaiah says, “If you are not firm in the faith, you will not be firm at all” (Is. 1:6 cf. 1 Cor. 16:13).
As we fight to be firm in the faith, it’s imperative that we have a holistic approach. The process of change, that is sanctification, is not a simplistic process. Here is one way of looking at the process: stimuli → thinking → emotions → actions → character. I think we see this same type of schema in 2 Peter 1:5-11.
We preserve in the faith as we think on God’s truth (1 Cor. 15:1; 2 Thess. 2:15). God’s truth is one of the positive forms of stimuli. It transforms (cf. Jn. 17:17).  We have faith not through some nebulous and opaque placement of faith. God uses means. He uses knowledge of various things. He uses experiences. He uses conversations with friends. He uses Scripture. He uses the gathered worship of the church. Thus faith is a fight. And continuing in the faith is a fight. This is because there are things we must do. God uses means to accomplish His ends.
So, what are some of these means that God uses to accomplish the end of us preserving us in the faith? How can we be firm in the faith?
First, God uses our mind (cognition) (cf. Prov. 4:23; 23:7; 2 Cor. 10:5; Rom. 12:2; Eph. 4:22-24; Phil. 4:8). We prepare our minds for action (1 Pet. 1:13) and set our hope fully on the grace that was brought to us at the revelation of the Messiah. We are supposed to be able to give a defensive for the reason we have hope (1 Pet. 3:15). We must use our minds and remind ourselves of truth so we will be firmly established (2 Pet. 1:12). We must recall that we do not follow “cleverly devised myths” (2 Pet. 1: 15, 16).
We must use our minds! In fact, God “has granted to us all things that pertain to life and godliness, through the knowledge of Him” (2 Pet. 1:3). In this category, God often uses the means of apologetics, meditation, study of devotional texts, and so forth to transform. Our cognitive belief has practical impact (when it is true belief). So 1 Peter 1:13: “you believe in Him and [thus] rejoice with joy that is inexpressible” (In this case, we see an emotional impact).
Second, God uses our emotions (emotive). For example, when we have prepared minds, minds set on hope (1 Pet. 1:13), we are sober-minded. We have emotions but they are grounded in truth. So, we have due fear for the LORD because we believe, with our mind, that He is our Father and will judge us according to our deeds (1 Pet. 1:17 cf. Rom. 11:20). Thus, we, because of cognitive and emotive reasons, reform our actions. In this category, God often uses community, worship, meditation, etc. to transform.
Third, God uses our actions (volition). Once we have right thinking and thus right emotions we have, or should have, right actions. We should no longer be “conformed to the passions of [our] former ignorance” (1 Pet. 1:14). We should no longer practice our “futile ways” (1 Pet. 1:18). Notice, “ignorance” and “futile” are both cognitive type terms but work out in the volitional realm. So, Peter says, “As He who called you is holy (both cognitive and emotive), be holy in all your conduct (volitional)” (1 Pet. 1:15). God uses worship, community, refraining from certain unholy practices, acts of charity, and so forth to transform us.
In this whole schema that I have sought to lay out, there is a back and forth. We should not fix lines where none is fixed. They intersect at many points and continue, like wires, woven together. Knowledge presses emotion and action forward and builds character. Yet, action (e.g. forcing one’s self out of bed early to read Scripture) affects our cognitive and emotive side.
“What we do flows out of who we are, but who we are is indeed shaped by what we do… We are changed by doing and we are changed by a self-conscious and iterative process that scrutinizes thoughts, affections, and actions for their faithfulness to a kingdom ethic, and then chooses certain actions and practices in response.”
So, saving faith is a continuing faith and an active faith. It makes use of means. That’s why we resist the devil by being “firm in the faith” (1 Pet. 5:9). Thus, we must remember, faith is not static. Neither does it stagnate. For God uses means.
“Therefore, brothers, be all the more diligent to confirm your calling and election, for if you practice these qualities you will never fall. For in this way there will be richly provided for you an entrance into the eternal kingdom of our Lord and Savior Jesus Christ” (2 Pet. 1:10-11).
 “You are her [Sarah’s] children, [i.e. the regenerate children of God] if you do good and do not fear anything that is frightening” (1 Pet. 3:6). However, then, the converse would also be true. If you don’t do good then you are not children of God. Thus, faith is active. God’s children do not fear anything that is frightening. Why not? Because they trust God. They do good. Why? Because they are transformed through faith.
 Paul’s logical connections are very often more explicit. I think that is often why he seems to be more liked in evangelicalism (as well as his corpus being larger). Ephesians 4:1 is clear enough, and in Romans 12 Paul even tells us that his application is logical (12:1, the ESV has “spiritual”). Thomas R. Schreiner says, “Paul used the term with the meaning ‘rational’ or ‘reasonable,’ as was common in the Greek language. His purpose in doing so was to emphasize that yielding one’s whole self to God is eminently reasonable. Since God has been so merciful, failure to dedicate one’s life to him is the height of folly and irrationality” (Thomas R. Schreiner, Romans [Grand Rapids: Baker Academic, 1998], 645 [italics mine].). In addition, Schreiner points out that “the word ‘bodies’ here refers to the whole person and stresses that consecration to God involves the whole person… Genuine commitment to God embraces every area of life” (Ibid., 644. Italics mine).
 http://bradbigney.files.wordpress.com/2013/03/diagrams_counselor.pdf, pages 3-4. “While God is always free to work miraculously and instantaneously, soul-change is typically a slow process that involves the replacement of old beliefs, affective responses, attitudes, and motives and patterns of relating to others with new ones, one at a time. Given what we know now of the neurological conditions of such change, it is not surprising why this process is gradual. Old neural networks must be shut down, and new ones must be constructed. None of this happens in genuine sanctification apart from the work of the Holy Spirt, but in this age most of the time God tends to work through the created order, and not take shortcuts. Though an incremental approach is sometimes hard for counselees to accept, such a stance, when grounded in justification, helps them to accept their present limitations and to be more realistic about the speed of their recovery, without undermining the ongoing call to grow in conformity to the image of Christ” (Eric L. Johnson, “Formation Counseling: A Middle Way,” 26-27).
 The whole of Scripture shows us this. Jesus for instance said, Love the LORD your God with all your heart, soul, mind, and strength (Mk. 12:30). Paul says “be transformed by the renewal of your mind” (Rom. 12:2) (cognitive), the Psalms say worship (e.g. Ps. 29:2) (emotive), other places say do righteousness (Jer. 22:3) (volitional). We see that this is the very process that leads to revival in the book of Nehemiah. Cognitive understanding (see esp. Neh. 8:7-8) lead to emotional experience (Neh. 8:9-12) which in turn lead to action (confession, 9:1-37; and covenantal resolve, 9:38).
 Thomas Goodwin said, “Thoughts and affections are sibi mutuo causae—the mutual causes of each other: ‘Whilst I mused, the fire burned’ (Psalm 39:3); so that thoughts are the bellows that kindle and inflame affections; and then if they are inflamed, they cause thought to boil” (“The Vanity of Thoughts”).
 “Such is the nature of man, that nothing can come at the heart but through the door of the understanding: and there can be no spiritual knowledge of that of which there is not first a rational knowledge” (Jonathan Edwards, “The Importance and Advantage of a Thorough Knowledge of Divine Truth”). However, Michael Emlet is also wise to point out that “The issue usually isn’t an information gap, but a desire/practice gap… Mere insight never changes anyone. People don’t change, not because they lack information but because they lack imagination that leads to action” (Michael R. Emlet, “Practice Makes Perfect?” 45-46).
 “Worship is one of the most transforming activities for us to engage in as Christians… When we become duly impressed with God our lives change because the things that matter to us change. We no longer want some of the things we previously desired. An overridding and overwelming passion for God himself, God’s people, and God’s kingdom purposes in this world replace those desires. True worship happens when we get a glimpse of God–who he is and what is is about–and just stand there in awe of him, being impressed and transformed down to the very depths of our being by the magnificent vision of the glory of our heavenly Father” (Richard E. Averbeck, “Spirit, Community, and Mission: A Biblical Theology for Spiritual Formation,” 38 in the Journal of Spiritual Formation & Soul Care). I think Eph. 5:17-21 is noteworthy here. See also “Singing, in the Body and in the Spirit” by Steven R. Guthrie in JETS and “Being the Fullness of God in Christ by the Spirit” by Timothy G. Gombis in Tyndale Bulletin.
 Michael R. Emlet, “Practice Makes Perfect?” 44. “Certain habits stir up corresponding affections and appetites; certain core affections and desires are expressed in corresponding habits. You can’t separate desire from practice” (Michael R. Emlet, “Practice Makes Perfect?” 42).
 The key thing is that we must persevere. It is not, fundamentally, about whether the person was or was not ever regenerate. I happen to believe that if one does not persevere then they were never regenerate. However, that discussion is not the main point of Scripture. Rather, Scripture is saying persevere, believe, obey! That, it must be seen, is the main thing.