Crucifying the flesh is about denying it its cravings and starving it to death. That comes with an attitude of total submission to God and a desire to please Him above all, especially above oneself. People who belong to Jesus have the Holy Spirit to put to death the deeds of the body (Romans 8:12-13). But, in repentance, the point where one responds to the call of Jesus and denies him/herself, takes up his/her cross to follow Him (Mark 8:34), the cross deals its fatal blow to the "old man." So, these can be written about such persons who have followed that path and come to (belong to) Jesus:
Galatians 5:24
Those who belong to Christ Jesus have crucified the flesh with its passions and desires.¹
Romans 6:5-7
5 For if we have been united together in the likeness of his [Jesus'] death, certainly we also shall be in the likeness of his resurrection, 6 knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin. 7 For he who has died has been freed from sin.
Being dead with Christ means to no longer be a slave of sin who is sinning (John 8:34-36, Romans 6:16-18). Romans 6:7 could not make the point of being "dead" clearer, saying "he who has died has been freed from sin." That is a death by the cross.
Remark that the cross (that kills the sinful passions that arise from having a body or "flesh") is largely not being preached nowadays (2 Timothy 4:3-4 confirmation), and people are being declared "born again" through some way that the Bible does not teach. People who are affected by false teachings presented as the Gospel of Jesus Christ never in fact die in the way the Bible speaks of. Therefore, most can't relate to being dead to sin and alive to God (Romans 6:11) in a factual way, but usually only through mental gymnastics. And as a result of omitting the cross from the preaching of the Gospel, or simply not preaching true biblical repentance, 'salvation' in this present day Christian world, for most, means something else than being set free from bondage to sin as Jesus taught (John 8:31-36).
Philippians 3:18-19
18 For many, of whom I have often told you, and now tell you with tears, live as enemies of the cross of Christ, 19 whose end is destruction, whose god is the belly, and whose glory is in their shame, who think about earthly things.
But Christians are rightly so exhorted:
Colossians 3:5-10
5 Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. 6 On account of these the wrath of God is coming. 7 In these you too once walked, when you were living in them. 8 But now you must put them all away: anger, wrath, malice, slander, and obscene talk from your mouth. 9 Do not lie to one another, seeing that you have put off the old self with its practices 10 and have put on the new self, which is being renewed in knowledge after the image of its creator.
These exhortations are necessary for followers of Jesus because a person only needs to feed his/her flesh that should have been put to death in Christ (by the cross), for it to come back alive and it will surely rule him/her life and drag him/her right back to bondage to sin worse than before (e.g. 2 Peter 2:20-22). There is then no longer freedom in Christ to speak of if that happens. That's what would be called "losing salvation." The devil is always seeking whom he may devour, so Christians are forcefully warned (1 Peter 5:8, Acts 20:29-31).
Explore further:
Crucify The Flesh - (video playlist)
Take Up Your Cross - (video playlist)
Suffer The Cross To Overcome Addictions
Struggling with Lust? (Message for Men)
The Resurrection of Jesus
1. Belonging to Christ implies having received the Holy Spirit (Romans 8:9), which is only given to those who obey God and repent (Acts 2:38, Acts 5:32, 2 Timothy 2:19).
