The book of Job mentions "the satan" as part of the heavenly court (Job 1:6; 2:1). (The heavenly court is a gathering in heaven where God meets with his angels.) In Hebrew, satan means an adversary or accuser in court (see Job 1–2; Zechariah 3:1). God sometimes uses angels as adversaries for righteous judgment and to oppose wrongdoers (for example, Numbers 22:22, 32, where satan is often translated as "oppose"; see also 1 Kings 22:19–23).
The Old Testament suggests the accuser has a demonic nature. But it was in the time between the Old and New Testaments that Satan became associated with the serpent in Eden (see Wisdom of Solomon 2:24). The New Testament calls the chief demon "Satan" (Revelation 20:2). The New Testament uses other names like:
The devil (Matthew 4:1–11)
The tempter (1 Thessalonians 3:5)
Beelzebul, the prince of demons (see notes at Matthew 12:24; Luke 11:15)
The evil one (Matthew 13:19, 38; 1 John 2:13–14; 3:12; 5:18)
Belial (see note at 2 Corinthians 6:15)
The deceiver (Revelation 12:9)
A huge red dragon with seven heads (Revelation 12:3, 9)
Ancient serpent (Revelation 20:2)
A murderer and the father of lies (John 8:44)
Satan did many evil things against God and people. He made David count his army when he should not have (1 Chronicles 21:1; compare 2 Samuel 24:1). Satan tried to tempt Jesus to do wrong and later helped Judas betray Jesus (Mark 1:12–13; John 13:27). He wanted to test Peter's faith like he tested Job (Luke 22:31). He trapped people in sin (Acts 26:17–18). He used lies to oppose God's people (1 Corinthians 7:5; 2 Corinthians 11:14). In the end, God will defeat and imprison Satan, overcoming the adversary of God's people (Revelation 12:9; 20:2, 10).
Passages for Further Study
Numbers 22:22, 32; 1 Chronicles 21:1; Job 1:6–2:7; Zechariah 3:1–4; Matthew 4:1–10; 12:24; 13:19, 38–39; 16:23; Mark 1:13; 4:15; Luke 4:6; 10:17–20; 11:15; 22:3, 31; John 8:44; 12:31; 13:2, 27; 16:11; Acts 13:9–10; 26:17–18; Romans 16:20; 1 Corinthians 7:5; 2 Corinthians 2:10–11; 4:4; 6:15; 11:13–15; 1 Thessalonians 3:5; 2 Thessalonians 2:2–12; Hebrews 2:14; James 4:7; 1 Peter 5:8; 1 John 2:13–14; 3:12; 5:18; Revelation 12:3, 9; 20:2, 10