Does repent simply mean to change our mind or is some action required?

In both the Old and New Testaments, the word repent can mean –
a) To be sorry about or regret something or
b) To turn away from sin.

In the OT, the KJV translates two Hebrew words as “repent” –
The first is “Nacham” (H5162), which means to be sorry or regretful. An example is in 1 Sam. 15:35 (KJV) which says, “… the LORD repented that he had made Saul king over Israel”. In this verse, repented means that the Lord regretted or was grieved that He had made Saul king.

The second Hebrew word is “Shub” (H7725), which means to turn from sin. An example is in Ezek. 14:6 (KJV) which says, “… Thus saith the Lord GOD; Repent, and turn yourselves from your idols; and turn away your faces from all your abominations”. In this verse, repent means to turn away from evil.
From these two OT examples we see that repent can either mean to be sorry about something or to turn from sin.

In the NT, two Greek words parallel these two Hebrew words:
The first is “Metamellomai” (G3338), which means to care afterwards, to regret. An example is in 2 Cor. 7:8 (KJV) which says, “For though I made you sorry with a letter, I do not repent, though I did repent…”. In this verse, Paul repents (that is, regrets) causing sorrow.

The second Greek word is “Metanoeo” (G3340) which Thayer’s dictionary defines as, “to change one’s mind for better, heartily to amend with abhorrence of one’s past sins”. An example is in Act 3:19, 26 (KJV) which say, “Repent ye therefore, and be converted, that your sins may be blotted out… in turning away every one of you from his iniquities”. In these verses, repent means to have a change of mind and turn from sin for forgiveness.

These examples show that, in both the OT and NT, repent can mean to be sorry or regretful about something or it can mean to turn away from sin. When repent is associated with salvation it means to turn from sin, as Luke 13:1-9 (NIV) show. In this passage, vs.2, 4 set the context as sin and in v.3 Jesus said, “… unless you repent [turn from sin], you too will all perish”. In this verse, repent is Present (Continuous) Tense meaning that Jesus actually said, “… unless you continually repent [continually turn from sin], you too will all perish”. Then, in the parable of vs.6-9, Jesus said that if a fig tree (a believer) does not bear fruit then it will be cut down. This passage tells us that a sinner must turn away from sin and lead a holy, repentant life otherwise he will be cut down and perish.

Regarding salvation loss, in one sense it really does not matter what repent means. The fact is, Jesus said that we must continue to do it, whatever it is, otherwise we will perish. For example, if repent means to “eat an apple a day” then we must continue to eat an apple a day otherwise we will perish. This makes it obvious that salvation can be lost if we fail to continue to do whatever repent means.

Source: by Mick Alexander