The Greek noun misthos means wages, pay, reward, or recompense. It is used literally of payment for labor and metaphorically of the reward or judgment that comes from God. Every worker deserves their misthos (Luke 10:7; 1 Timothy 5:18). God is the ultimate paymaster — the one who 'repays each person according to what they have done' (Romans 2:6).
Misthos teaches that consequences are built into the moral fabric of the universe. Paul uses it to describe the church planter's reward at the judgment (1 Corinthians 3:8,14) and Balaam's 'wages of wickedness' (2 Peter 2:15). Jesus promises that even giving a cup of cold water will not go without misthos (Matthew 10:42). Theologically, reward is not earning salvation but God's gracious acknowledgment of faithfulness.