Paul writes in Romans 8:13, ‘if by the Spirit you put to death the misdeeds of the body, you will live.’
This introduces the important but neglected subject of ‘mortification’.
’Mortification,’ says J.I Packer in God’s Words, ‘is war.’ Four steps are involved in this warfare:-
1. We must know our enemy
We fight, not just sins, but the sinful nature which lies behind all instances of sinful actions. The unbeliever is a slave to sin, Rom 6:16-23. But the believer has had a change of heart and mind; he has renounced sin, and is determined to crucify the flesh and its lusts, Gal 5:24. But sin remains as a kind of devilish alter ago. The Christian therefore finds a conflict within himself, Gal 5:17. He wants to be perfect, but he never is, Rom 7:19-20.
‘Neither is it expressible with what vigour and variety sin acts itself in this matter. Sometimes is proposeth diversions, sometimes it causeth weariness, sometimes it finds out difficulties, sometimes it stirs up contrary affections, sometimes it begets prejudices, and one way or another entangles the soul, so that it never suffers grace to have an absolute and complete success in any duty.’ (Owen)
2. We must know our objective
If ignorance of our enemy is blindness, then ignorance of our objective is to fight aimlessly. He who aims at nothing achieves nothing. Our objective is to mortify sin; to put it to death so that it can trouble us no more. We will not achieve this objective in this life, but we are to progress towards it. We are not merely to resist attacks when they come, but to take the initiative against them.
(a) a life’s work: we do not cease from the fight until we die;
(b) a painful discipline: sinful habits can become so much part of ourselves that to attempt their destruction is like cutting off a hand, or plucking out an eye, Mt 5:29-30;
(c) but it is an effective discipline: every help is at hand to aid us in the fight, and every satisfaction is enjoyed by those who can look back at sins now conquered by the power of the Spirit of God.
3. We must know our superiority
Nobody has much heart for a fight which he believes he cannot win. But God obliges the Christian to expect success in this matter. In regeneration he has been made a ‘new creation’, 2 Cor 5:17.
(a) has implanted a new life-principle: we have been ‘raised with Christ, Eph 2:5 Col 2:12-13 3:1; we have had implanted in as a spontaneous affinity to God and godliness; to sin may be inevitable, but it is no longer natural;
(b) has dealt a death-blow to sin: this is an effect of our justification and regeneration, Rom 6:6; sin no longer has dominion over us, Rom 6:14; our part is to hasten sin’s inevitable demise. ‘However furious or stubborn sin may prove, however deeply it may have entrenched itself behind bad habits and temperamental weaknesses, sustained pressure cannot fail to uproot and rout it.’
(c) took up residence in the heart: he indwells the believer, Rom 8:9-11 1 Cor 6:19; he is present in person to oppose indwelling sin. He teaches the Christian to understand and apply revealed truths. He stirs up the Christian to obey and strengthens him as he does so.