Every Christian is involved in the war of personal holiness, every hour of every day. The easy-going Christian who doesn't understand the spiritual warfare will fail to honour the Scriptures, to live close to the Lord, to count for him. There's a very beautiful hymn of Watts, ‘Alas, and did my Saviour bleed, and did my sovereign die’, and in the 19th century an American songwriter added a refrain, which ends with the words, ‘And now I am happy all the day.’ The person who wrote that was a disastrously shallow Christian, and the people who sing that are disastrously shallow Christians, who've opted out of the war. Yes, there is a sense where we may joy in the Lord all the time, but the Christian life cannot be described as ‘happy all the day’, because of the battle against sin. We are so thrown by our failures and our sin, and we suffer setback and disappointment, and seek to repent and pledge ourselves once again. The casual Christian is far from living the Christian life. You can only fight it by faith in Christ, with the help of the Holy Spirit. You can only fight it aware of your need of divine help.
Consider the commands to mortify indwelling sin and the deeds of the flesh. It used to be called the doctrine of concupiscence. It's what was taught so explicitly and clearly by Augustine. It's what you'll find in the writings of Luther, and in Calvin. It's what you'll find in the Westminster Confession of Faith, chapter 5, article 6. It is taught in the Savoy Declaration of the Congregationalists, and in the Baptist Confession of Faith of 1689, following the Westminster. You find it even in the 39 Articles of the Church of England, the doctrine of concupiscence, framed for the 39 Articles by Thomas Cranmer, martyr himself. Concupiscence is a word that comes from the Latin and means intense desire. It is the doctrine that since the fall of man, he possesses a fallen human nature, a sinful nature. That sinful nature is like a boiling cauldron of desires and lusts down there in the heart. Man is a creature of great desires. Now if you are converted to Christ, the wonderful thing is that all the guilt which is attached to that cauldron of sin is borne away by Christ. You are a forgiven man, a forgiven woman. The cauldron in the heart will never condemn you to hell. But the problem is still there, even after conversion. You have a new nature, superimposed, a superior nature, which makes you capable of having a clean heart, but the old nature is still there. And its ‘motions’ – that's the old-fashioned word of the confessions – its suggestions, its desires, are still active. The way of dealing with them in the Bible is that as they rear into your mind, you put them to death, you mortify them with urgent prayer to God, and you divert your mind and your thoughts to better things. They are sinful thoughts, and you've got to fight them or you will yield to them.
Does it mean that if you fight the good fight of faith, then at the end you will get the crown of eternal life? The Apostle Paul does say exactly that in a separate illustration where he uses the illustration of the race, and at the end of the race you receive the crown, but this time he alters the picture and he shows us another very precious truth. To fight the good fight of faith means that even now you lay hold on eternal life. Some part of eternal life is to be had now, and you can lay hold on it in this life. Of course you can't lay hold on all of it, because most of it lies beyond the grave in the glorious eternal inheritance, when you go to be with Christ. Then you will have the amazing experience of your soul being taken up to God and going into the paradise of Christ with him, and then eventually receiving your resurrection body, and being with the people of God and with the Lord for all eternity. But some aspects of eternal life are given to us now, and we have got to lay hold on them. How do we do that? By fighting the good fight of faith. What does it mean to grasp eternal life? It means to grasp experiences which largely belong to heaven. It is about closeness to God, holiness, tasting his power and his goodness. You can have great victories in holiness, and great blessings, wonderful assurance, a tremendous sense of the power and the closeness of your God. You can have his blessing in your life, but you've got to lay hold on it, even as a Christian, otherwise, although it is in the future, you won't taste much of it now.
Are you fighting to keep and to build up your personal faith? It's something you've got to be doing every day. You cannot leave it. If you are saved, you are saved entirely by the grace of God. You could do nothing to help yourself. But now you are saved, you have got a job to do. You’ve got a contribution to make to your spiritual well-being. You've got to fight the good fight of faith. In a fight there is an enemy, and a fight means interacting with the enemy. The first enemy is self-interest. Self-interest is going to try to bring me down. I have got two natures, don't forget. I have got the old nature the fallen nature, the old me, and then I have got a new nature graciously given me by the Saviour at my conversion. I have got to strike the first blow against the old nature – what I want to do, what I want to have. I recognize the move that's coming, the strategy, the hold which sin within seeks to put upon me. I recognize it and I know how to break it. I am going to reject this selfish thought, this personal desire. The sins of the flesh – pride, temper, greed, desire and self-will; we recognize the blows that are coming and we've got to parry them away, and pray to God for help. We cannot afford to start the day on autopilot, blissfully unaware of the fight. The devil who is wrestling with us says, ‘I have got a hold designed just for this person, which will throw him off course and distract him’, and in comes some wild alarm, some concern, and we perhaps overreact and make a great big thing of it, when really we could have been much more sensible and disciplined.
But then there is a wider sense in which we have to fight this fight. We have got to fight for the faith, all of us: there's no exemptions. Every one of us is involved in propagating the gospel and defending the gospel. How is your witness? Do you witness in word? Are you seeking to be a representative of the Lord? Do you speak for him as individuals? Not only so, but do you represent him in your life? God allows all kinds of trials and tribulations, disappointments, persecutions to come upon his people. The key thing is how do we handle these things. This is part of our witness without saying a word. When people know we belong to the Lord they are noticing how we respond to all the trials of life. People are watching us. Do we prove that we have a hold upon the Lord and that we have access to divine resources? Or do they floor us and do we flounder and give a demonstration of weak and carnal people?
Some believers do not fight. They have come to Christ; they have repented of their sin; they have desired heaven, and God has worked in their hearts. They have been converted and come to the Lord, but after that they don't fight the fight of faith; or maybe they do, but just with one hand every now and then warding off the odd blow. The rest of their body and soul is devoted to the earthly affairs and their home and their family and their career. There is no fight going on. You can't fight like that. You can't live the Christian life with half your mind and your heart on things in this life, promoting your interests, with all kinds of aspirations and just a small amount of attention to fighting against the temptations of the devil. The Lord demands full attention. If you try to dream through the Christian life, you will be a believer who suffers many injuries and setbacks.
Sometimes the Lord's people do not watch. The watch is so poor that almost every innovation that the devil brings in succeeds. Here is something novel, some new method that somebody has dreamed up, and the response it, ‘Let's take them all on board.’ The good fight of faith means we are striving and putting forth all our efforts to promote the gospel, to seek souls, to persuade them about the things of God. At the same time we are watching our rear, watching our flanks. We are defending the truth that God has given us, keeping the gospel pure, keeping the methods simple and biblical, so that we are locked in to the power of God.
The doctrine of concupiscence – the Catholic Church denies it. The Catholic Church says that when you're baptized as a child, through the rite of baptism, magically, inward sin is rendered impotent and it no longer is sinful. ‘Aha! You mean my sinful thoughts I don't have to feel bad about? They're not sinful, not unless you carry them out and do the deed that they suggest.’ That is the opposite of biblical teaching and in the different articles in the Council of Trent in the 16th century, the Catholic Church actually spells out what the Apostle Paul says and then says, but the Church says … – yet another of many examples in the documents of Trent where what the Bible says is put down in favour of what Catholic Church tradition says. But here is the astounding thing: there are evangelical teachers today, – who believe the Bible but seem to have forgotten their doctrine or be ignorant of its implications – who are saying, ‘Temptation is not a sin; only the execution of the deed is sin.’ That is completely contrary to the doctrine that there is sin in us, and the sin incurs guilt. The word concupiscence today tends to mean exclusively sexual sin, but that's not the traditional meaning of the word. The doctrine of concupiscence refers to all kinds of temptation, temptations to selfishness, pride, greed, hatred, anything, including sexual temptation. All temptation is sinful although there are some exceptions. If a sudden temptation surprises you and it comes at you from outside and it's abhorrent to you and you reject it at once, there is no sin in your thought life. Supposing you are walking along the road with somebody, and you don't know them very well, and they suddenly say, ‘Let's smash this window and break into this shop and steal that.’ You are shocked and you reject the idea at once. Well, that doesn't come under the doctrine of concupiscence. It's bounced off you as soon as it's come, but unfortunately most sin isn't like that. When the devil tempts, he knows you've got an old nature. He knows that you've got wrong desires and he stirs them up. So this temptation enters into you and it's considered, it's given hospitality, it's thought about. Well supposing somebody is subject to sexual temptation, it may be heterosexual, it may be homosexual, same-sex attraction; it's the same for both. When that thought comes, you hesitate with it, the thought is even considered. If you don't believe in the doctrine of concupiscence, that this incurs sin and this is evil and somebody has said to you that it isn't sinful unless you do it, then you may very well be tempted to relish that thought and to gaze at that person in a fallen way. This is the cruellest doctrine because you're encouraging people to play games with their sin and to entertain it. Perhaps you stirred it up, perhaps you've been looking at the wrong images and you haven't stopped yourself, and prayed and mortified it and it's got a grip of you, and the temptation now comes more often. How did it get to this point? Because you believe the lie that temptation isn't a sin. The kindest thing is to correct that false teaching and to recognise that even the thought life is sinful and has to be mortified. This is the doctrine of concupiscence. The Lord Jesus Christ ‘was in all points tempted like as we are, yet without sin’ (Hebrews 4:15). Ah, they say, temptation is not sin. How foolish! He was the Lord Jesus Christ. He is the only one of whom this could be said – ‘tempted in all points, yet without sin’ – because he did not have a sinful nature.