Scripture often refers to faith and repentance in tandem, and the two correspond closely in the life of the believer. Turning away from sin in repentance is the natural extension of turning to Christ in faith.
At the same time, there is an important distinction between the two. Repentance should never be dismissed as merely another word for belief:
The Greek word for “repentance” is metanoia . . . Literally it means “afterthought” or “change of mind,” but biblically its meaning does not stop there. As metanoia is used in the New Testament, it always speaks of a change of purpose, and specifically a turning from sin. In the sense Jesus used it, repentance calls for an abandonment of the old life and a turning to God for salvation. Such a change of purpose is what Paul had in mind when he described the repentance of the Thessalonians: “You turned to God from idols to serve a living and true God”
1 Thessalonians 1:9
9 For they themselves report about us what kind of a reception we had with you, and how you turned to God from idols to serve a living and true God,
Throughout Scripture we see the call to repent from sin and turn to God. Christ warned His followers of the eternal consequences of sinful rebellion, saying “Unless you repent, you will all likewise perish”
5 “I tell you, no, but unless you repent, you will all likewise perish.”
Paul concluded his sermon on Mars Hill with a command to repent in light of God’s judgment. “Therefore having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent, because He has fixed a day in which he will judge the world in righteousness”
30 “Therefore having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent,
31 because He has fixed a day in which He will judge the world in righteousness through a Man whom He has appointed, having furnished proof to all men by raising Him from the dead.”
Some argue that calling sinners to repent is adding works to the gospel. But God’s Word is clear that true repentance cannot be mustered up from the unregenerate soul. Instead, like faith, repentance is a gift from God.
18 When they heard this, they quieted down and glorified God, saying, “Well then, God has granted to the Gentiles also the repentance that leads to life.”
2 Timothy 2:25-26
25 with gentleness correcting those who are in opposition, if perhaps God may grant them repentance leading to the knowledge of the truth,
26 and they may come to their senses and escape from the snare of the devil, having been held captive by him to do his will.
Clearly, the biblical concept of faith must lead to obedience. “Believe” is treated as if it were equal with “obey”
36 “He who believes in the Son has eternal life; but he who does not obey the Son will not see life, but the wrath of God abides on him.”
Acts 6:7 shows how salvation was understood in the early church:
7 The word of God kept on spreading; and the number of the disciples continued to increase greatly in Jerusalem, and a great many of the priests were becoming obedient to the faith.
Obedience is so closely related to saving faith that Hebrews 5:9 uses it as a synonym:
9 And having been made perfect, He became to all those who obey Him the source of eternal salvation,
Obedience is the inevitable manifestation of true faith. Paul recognized this when he wrote to Titus about “those who are defiled and unbelieving. . . . They profess to know God but by their deeds they deny Him”
15 To the pure, all things are pure; but to those who are defiled and unbelieving, nothing is pure, but both their mind and their conscience are defiled.
16 They profess to know God, but by their deeds they deny Him, being detestable and disobedient and worthless for any good deed.
To Paul, their continuous disobedience proved their disbelief. Their actions denied God more loudly than their words proclaimed him. This is characteristic of unbelief, not faith, for true faith always produces righteous works. As the early Reformers were fond of saying, we are justified by faith alone, but justifying faith is never alone.
The biblical testimony is clear. The gospel call is a call to repent and believe. You can’t have one without the other, and you can’t do either without God empowering those responses.
If we are to faithfully proclaim the message of salvation, we must establish God’s holiness in contrast to man’s depravity. We must present the solution to that humanly undefeatable problem by proclaiming the life, death, and resurrection of the Lord Jesus Christ. It is at that point that we are to issue the call to repent and believe, and leave the miraculous work of conversion in God’s sovereign hands.