There is no doubting that Satan knows how to tempt us today. Satan knew how to tempt our Lord in the wilderness (Matt. 4:1-11; Luke 4:1-13). Satan knew the areas in which he could tempt Jesus. Satan knew that he could tempt Jesus with turning the stones into bread (Matt. 4:3; Luke 4:3), because Jesus had been fasting for forty days and forty nights and was hungry (Matt. 4:2). Satan went on to tempt Jesus in two other areas as well.
We can make Satan’s job more difficult though if we are growing in the Christian graces (2 Pet. 1:5-7), progressing from the milk of the word to the meat of the word (Heb. 5:12-14), and studying to show ourselves approved (2 Tim. 2:15). If we are doing those things, then it will be more difficult for Satan to tempt us with the cares of this world (Luke 8:14).
2. Satan knows how to deceive us.
John 8:44 describes Satan as the father of lies. The verse says that Satan, “abode not in the truth, because there is no truth in him.” Satan does not care about our well being because he only seeks to destroy us. Peter wrote, “Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour” (1 Pet. 5:8). Since Satan’s objective is to destroy us, he will use any means necessary, including deception.
3. Satan knows Scripture.
Not only does Satan know how to tempt and how to deceive mankind, but he also knows Scripture. When Satan tempted Jesus in the wilderness, he quoted from Scripture. When Satan took Jesus up to the pinnacle of the temple (Matt. 4:5), he quoted Psalm 91:11-12. The fact that Satan knows Scripture, makes it all the more important for us to know Scripture. It is important that we follow the same exhortation that Paul gave to Timothy in 2 Timothy 2:15, "Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth." Jesus used Scripture (and He used it correctly) when He was faced with temptation (Matt. 4:4, 7, 10; cf. Deut. 8:3; 6:16; 10:20). We ought to be ready and to know how to correctly apply Scripture, because there are many in the world that will use it deceitfully against us.