A. μετανοέω/μετάνοια in the Synoptic Gospels
μετανοέω/μετάνοια is a major theme and commandment of the Gospel call, which is ubiquitous in the Synoptic gospels and Acts. In most English Versions, μετανοέω/μετάνοια translated as "repent/repentance" -basically means, "to be sorry again." But the primary lexical idea of the words is to change and turn (around) of whole life, as the Hebrew equivalent in LXX, shuv - to return.
"Repentance" is not "confession." And the famous evangelistic phrase, "Repent of your sin," is NOT a Biblical term, but "Repent for the forgiveness of sin, and the salvation" is a solid Biblical term (Mk 1:4; Lk 3:3; 24:47; Ac 2:38).
In the Scripture, μετανοέω never used to mean merely feeling remorse or regret and do penance for wrongdoings. Instead, μετανοέω used in the sense of turning our life directed toward God resulting from a change of mind/ heart; from the old self-centered life to the God-centered new life in Christ; and for Jews, from the work of the Laws to believing in Jesus, the Gospel.
Jesus in Mark 1: 15 (and John the Baptist, Mt 3:2) speaks to Jews to μετανοεῖτε -Turn ye, not Repent ye (=be sorry). For, in the message, Jesus declares the new Messianic era has come, and now Jews must turn (μετανοέω ) to believe in the Gospel, from the belief in the works of the Laws. Nowhere in the Scripture, turning to believe in the Gospel is a sin that needs repentance /contrition (be sorry). Therefore, the proper translation of μετανοεῖτε is Turn ye, not, Repent ye (=Be sorry ye).
[A note: Interestingly, CEV, GNT, and God's Word Translation have rendered μετανοέω as - Turn back to God; Turn away from your sin, and Change the way you think and act; LSV-convert and believe; Amplified -repent [change your inner self-your old way of thinking, etc.]
Bible is clear, without turning to God, feeling and being sorry for wrongdoings will not get us the forgiveness of sins, much less salvation. Turning to Jesus and believing the Gospel is the only way for eternal life in the kingdom of heaven. It is the prerequisite for salvation, as seen in the thief saved on the cross and the prodigal son (Lk 23:43; 15:11-32). As the evangelical buzzword - "Turn or burn," we need to turn to Jesus for receiving the forgiveness of sin, salvation, and the restoration of the severed relationship.
The Gospel call to turn (μετανοέω) and believe in the Gospel is for all living souls whose hearts/minds are far away from YHWH (Isaiah 29:13; Matt 15:8) -the Jews, gentiles, the unbelieving believers, the backsliders, including the apostates (Jer 3:22). It is always a good time for μετανοέω/μετάνοια (to turn/turning). It is never too late, as in the case of the thief on the cross and the prodigal son. The loving Father is calling all to μετανοέω/μετάνοια, as the old hymn goes: Softly and Tenderly Jesus is Calling, 1 & 4 stanzas (W.L. Thompson, 1800):
"Softly and tenderly Jesus is calling;
Calling for you and for me.
See on the portal, He's watching and waiting;
Waitin' for you and for me.
O for the wonderful love He has promised,
promised for you and for me!
Though we have sinned, He has mercy and pardon,
pardon for you and for me.
Ref: Come home, come home; you who are weary,
come home; Earnestly, tenderly,
Jesus is calling, calling, O sinner,
In the Synoptic Gospels, Jesus and John the Baptist began their ministries by declaring, "Repent ye, rather "turn/return Ye" for the kingdom of heaven is at hand." μετάνοια means turning/returning to God, a prerequisite for salvation, and μετανοέω is our taking the vital steps unto justification and reconciliation with the loving God.
Jesus is saying just as the Galileans and 18 people of Siloam ended in the ill fates, they, all the Jews, will meet the same consequences if they do not μετανοέω - turn from and return to God. The nation of Israel fell to Rome in AD 70. The Gospel call goes out to all humanity:
"The time is fulfilled, and the kingdom of God is at hand; Μετανοεῖτε
-turn - and believe in the gospel!