Why should we put on the full armor of God? We should put it on because the Lord commands us to (cf. Luke 12:35). This alone ought to be sufficient reason. We are to recognize his authority to direct our lives. Who are we to disobey the Lord? But this is an age of incredible spiritual immaturity. I speak of us all. Someone has said that American Christianity is 3,000 miles wide and a half an inch deep. Therefore, let’s think of some other reasons.
Satan has a great advantage in battle when we fail to put on and then use the weapons of our warfare (cf. Luke 4:13; 16:21-23). Imagine going tent camping and then failing to zip up the doors to keep out the mosquitoes and other nasty bugs. That would be failing to use your advantage. Whatever opportunity the evil one now misses by our diligence, he hopes to find again by our negligence. He hopes that we will be tired out by continual duty. Satan is a skilled hunter (1 Peter 5:8). He watches the tracks of our feet for an indication of the direction of our hearts (Psalm 119:10). Beware of youthful over-activity, middle-aged laziness, or senior sleepiness. We need to be like Eleazar in battle (2 Samuel 23:9-10) or like Joshua (Joshua 10:12-14).
It is hard to reactivate a habit of grace when it has fallen into disuse (Song 5:3). Sometimes this happens because of the shame of guilt. Is there anyone reading that is too ashamed to serve because you have really messed up your Christian life? I know one way that you can be whiter than snow. The blood of Christ never loses its power! Remember that after David was forgiven he went out to fight again. Sometimes this happens from sheer difficulty. When a room has been messed up, it is harder to clean than when it is kept in constant order. One sin tolerated will eventually lead to greater problems. Learning to play a musical instrument and then neglecting to practice and then trying to play again is difficult. Sometimes our lack of spiritual responsiveness happens from being under false teaching. Human-centered or free will teaching marinates a soul in self-sufficiency. Legalism bakes the heart hard in self-reliance. Transforming experience errors of various types send a soul on an empty search for something besides Jesus Christ. Seek fellowship with the Lord Jesus Christ, not an experience!
In one sense it doesn’t matter how someone falls into a trap. What matters is how to get out of it. The only way is through a fresh faith in Jesus Christ, the Son of God. What can I do to persuade you of our Lord’s surpassing worth and all-sufficiency?
We should put our armor on for the sake of our fellow soldiers. A soldier who does not know how to use his weapons is a danger to his own comrades (cf. Hebrews 5:11-14). Good doctrine with an evil lifestyle is like a loaded gun in the hands of a two-year-old. Incorrect doctrine with good intentions is like carrying out attacks without regard to where the enemy is—many are injured by “friendly fire”. The unwise conduct of one professing believer makes the situation worse for many others. Even when the person does not fall into a scandal, he or she cannot help other saints, as should be the case.
We can only put on spiritual armor by faith. This action is a daily necessity for every follower of Christ. You and I must be prepared for battle! However, you cannot put on spiritual armor unless you first know the Lord. Are you a follower of Jesus Christ? Are you united to him by faith? Do you desire to fellowship with the Lord? True Christianity is a relationship with the risen Lord, and not an empty practice of duty. Make sure that you know the Lord before you try to follow him.
Grace and peace, David