"For Demas has forsaken me, having loved this present world..." (2 Timothy 4:10)
The above text, 2 Timothy 4:10, is the third and final mention of Demas in Scripture. In Colossians 4:14 he is listed as one sending greetings to the church at Colossae. In Philemon 24 he is named as a fellow-worker of Paul. In 2 Timothy 4, though, he is identified as a deserter from the Lord's work because he "loved this present world."
We are not told whether his love for the world was centered on any one thing. We are told only that he loved it and what that love for the world caused him to do. Of course, Christians are commanded not to love the world (1 John 2:15-17). Sadly, though, many today are like Demas and set their affections on it and its allurements with no regard for what it will cost them.
We often speak of "costly love affairs" whether in fiction or real life because those affairs cause homes to be broken, children to suffer, reputations to be ruined, wealth to be sacrificed, etc. Yet, none has ever been costlier than the love affairs Demas and others like him have had with the world. Consider some of the costly consequences of his affair.
Loving the world carries the highest price one can pay for anything: to be as the Gentiles of old, without God and without hope (Eph. 2:12). Continued fellowship with God requires walking with Him, in accordance with His will (1 John 1:5-7).
Friendship with the world makes one an enemy of God (Jas. 4:4). 1 John 2:15 states that anyone who loves the world does not have the love of the Father in him.
The one who claims to be a Christian, believing he is still in God's favor, but who flirts with the world is only deceiving himself. He must be made to realize the great cost of unfaithfulness -- his soul (Matt. 16:26).
In addition to hurting himself, Demas did great damage to the cause of Christ. In abandoning it, he deprived it of a devoted worker and robbed it of all the good he might have accomplished had he remained faithful. We can only wonder how many lives he could have helped if he had stayed loyal to the Lord. He wasted his knowledge and abilities.
There is also the matter of his influence. Others, most likely, became disheartened and discouraged by his example. He was probably a discouragement to his family and friends for no one can do as he did without encouraging others to do the same (Prov. 1:10-15).
Like every willful sinner, he crucified the Son of God anew and put Him to an open shame (Heb. 6:4-6; 10:29).
The actions of Demas robbed the world of the flavor of righteousness imparted unto it by godly living. It snuffed out another desperately needed light in a sin-darkened world (Phil 2:15). It deprived the worldly of the good example of one who lives and teaches the truth.
Someone has rightly said, "Every 'Demas' who leaves the truth makes it a little more difficult for some 'Cornelius' to learn the truth or some 'Timothy' to be reared in it."
Demas' love affair with this world was certainly costly. Most tragically, if there was no repentance on his part, it cost him his soul (Matt. 16:26). Doing as he did, hurts all and profits no one. Do not make the mistake of Demas. Do not love this present world.