it-1 p. 612
Demas
Colossians Study Notes—Chapter 4
New World Translation of the Holy Scriptures (Study Edition)
Paul's Fellow Workers—Who Were They?
What Is Truly Valuable?
(Deʹmas) [possibly a shortened form of "Demetrius," meaning "Of (Belonging to) Demeter"].
A onetime fellow worker of the apostle Paul. Demas was in Rome with the apostle during his first imprisonment there, his greetings being included in letters to the Colossians and to Philemon. (Col 4:14; Phm 24) When Paul wrote to Timothy during his second imprisonment, Demas had forsaken the apostle and departed to Thessalonica, perhaps his hometown.​—2Ti 4:10.
The exact nature of Demas' forsaking Paul 'because of his love for the present system of things' is not disclosed. The apostle does not say Demas became an apostate or opposer. Perhaps Demas' love for material things and worldly pleasures became stronger than that for spiritual things. Fear of martyrdom with Paul may have caused Demas to seek a safer place and thus preserve his life in the then-existing system of things. In any event, when conditions became unfavorable, Demas failed to use his marvelous opportunity to strengthen his brother Paul.