27 As soon as Judas took the bread, Satan entered into him.
"What you are about to do, do quickly," Jesus told him, 28 but no one at the meal understood why Jesus said this to him.
Sadly, our Lord’s conviction had proved ineffective for Judas. Grace upon grace had been extended to the betrayer by Jesus yet he remained steadfastly unchanged. Frighteningly, when he granted access to evil into his heart, he abandoned himself to the power and conduct of Satan. We had seen earlier in the chapter where Satan had prior prompted the turncoat to betray his Master:
2 The evening meal was being served, and the devil had already prompted Judas Iscariot, son of Simon, to betray Jesus. John 13:2 (NIV)
Never having given Christ Lordship of his heart, Judas remained open to the advances of the adversary. I am reminded of the following Proverb which depicts one whose fortification wall of self-control is breached:
28 Like a city whose walls are broken down is a man who lacks self-control. Prov 25:28 (NIV)
The walls of a city in Biblical times were its strength. Weak or breached walls equated to vulnerability and openness to entrance of enemy forces. The same holds true for a life. When we do not fortify our walls of self-control – places we know where we are weak, we open ourselves up for an attack of the evil one of which, I might add, we are no match. First he suggests, then he commands. First he knocks at our doors asking permission then when admitted he takes complete possession - ruling like a tyrant. As believers we are sealed with the Holy Spirit and cannot, like Judas, be possessed by Satan but (and this is a BIG but) we can be so oppressed by the adversary through a breach in our defenses that we perhaps feel possessed. If he cannot keep us from being saved he will certainly strive to keep us from being used for kingdom work. Let us not be ignorant of his devices. James tells us to render obedience to God and to resist the devil and he will flee – Satan, of course, being no match for God:
7 Submit yourselves, then, to God. Resist the devil, and he will flee from you. James 4:7 (NIV)
While Satan is not omniscient he is a very good study and watches where we are the weakest, orchestrating and customizing our temptations in an effort to ensnare and trap us. He is supremely evil, hateful and deceitful yet he masquerades around as an “angel of light” taking captive those who are unaware of his vile and wicked schemes. Our safety lies in resisting him – not listening – giving no credence to his first advances. Paul tells us that as believers we are to be strong in the Lord, clothing ourselves with the full armor of God which enables us to withstand his evil ways.
10 Finally, be strong in the Lord and in his mighty power. 11 Put on the full armor of God so that you can take your stand against the devil's schemes. Eph 6:10-11 (NIV)
Interestingly, the word translated “schemes” in the above verse is from the Greek word “Methodeia” meaning “to work by method; the following or pursuing of an orderly and technical procedure in the handling of a subject.” Hebrew-Greek Key Word Study Bible – New Testament Lexical Aids. In other words, just as God has a wonderful plan for our lives so too Satan has a plan for evil and demise. Satan counterfeits whatever God does and he is very good at it – he has had lots and lots of practice. We are to resist the devil and stand firm in the full armor of God – in His power and mighty strength:
12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. 13 Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand. 14 Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place, 15 and with your feet fitted with the readiness that comes from the gospel of peace. 16 In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one. 17 Take the helmet of salvation and the sword of the Spirit, which is the word of God. 18 And pray in the Spirit on all occasions with all kinds of prayers and requests. With this in mind, be alert and always keep on praying for all the saints. Eph 6:12-18 (NIV)
This is why we are told in Jude the following regarding Satan and his ways:
8 In the very same way, these dreamers pollute their own bodies, reject authority and slander celestial beings. 9 But even the archangel Michael, when he was disputing with the devil about the body of Moses, did not dare to bring a slanderous accusation against him, but said, "The Lord rebuke you!" 10 Yet these men speak abusively against whatever they do not understand; and what things they do understand by instinct, like unreasoning animals--these are the very things that destroy them. Jude 1:8-10 (NIV)
“Let us watch jealously over our hearts, and beware of giving way in the beginnings of sin. Happy is he who feareth always, and walks humbly with his God. The strongest Christian is the one who feels his weakness most, and cries most frequently, ‘Hold Thou me up, and I shall be safe.’” John Ryle