The word repentance means deep sorrow; regret for any past action, wrongdoing, conviction of the heart, or sinful ways. A sincere turning away in both mind and heart from mans sinful ways to God.
To repent in relation to salvation is to change your mind from rejection of Jesus Christ to the faith of Jesus Christ, to recognize that He is indeed "Lord and Saviour".
And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
-Mark 1:15
And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.All the Prophets, apostles and even Our Lord and Saviour Jesus Christ called for repentance.
-Romans 12:2
From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.
-Matthew 4:17
I came not to call the righteous, but sinners to repentance.The goodness of God leads us to repentance.
-Luke 5:32
Or despisest thou the riches of his goodness and forbearance and longsuffering; not knowing that the goodness of God leadeth thee to repentance?By Gods Love and great Mercy, when we repent, admitting we have sinned against God,believe in Jesus Christ alone and what He did for us at the cross of Calvary.
-Romans 2:4
God then is able to restore that relationship with Himself by His Grace, leading us to receive the gift of the Holy Spirit, to continue to guide us into all truth ,the renewing of our minds through Gods word, personal relationship in prayer, and the inwardly and outwardly changing of our lives. A person who has truly repented from the rejection of Christ to faith in Jesus Christ will give evidence of a changed heart, mind and life showing the love of God.