The Hebrew word for repentance is Teshuvah. It means to regret sin you have done, and resolve never to do it again.

Teshuvah means to return (to God).

When we repent, we turn our back on the world (of sin) and turn to Jesus. When we repent, it is in response to our love for Jesus.

"Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him. For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world. And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever." - 1 John 2:15-17 KJV

Jesus said,

"And when he had called the people unto him with his disciples also, he said unto them, Whosoever will come after me, let him deny himself, and take up his cross, and follow me." - Mark 8:34 KJV

When we repent, turning our life to Jesus, we deny our self. We turn from our sinful desires and lusts and give our heart and our love to Jesus. Repentance is crucifying our sinful desires out of love for Jesus, just as He crucified His own flesh out of His love for us. We follow Jesus’ death by repentance, His burial by water baptism in Jesus name, and His resurrection by receiving the gift of His Spirit to live a new and holy life.

Peter preached repentance when he preached the Gospel on the Day of Pentecost.

"Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. ... And with many other words did he testify and exhort, saying, Save yourselves from this untoward [perverse, wicked] generation." - Acts 2:38, 40 KJV

It is by the goodness of God that He leads us to repent.

 "Or despisest thou the riches of his goodness and forbearance and longsuffering; not knowing that the goodness of God leadeth thee to repentance?" - Romans 2:4 KJV

By the Gospel: repentance – baptism in Jesus name – receiving the gift of His Holy Ghost, we are a glorious church, holy and without blemish.

"Husbands, love your wives, even as Christ also loved the church, and gave himself for it; that he might sanctify and cleanse it with the washing of water by the word [word = ‘the gospel,’ according to Thayer’s Greek Lexicon] That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish." - Ephesians 5:25-27 KJV

It is because of the longsuffering of God that He has not yet come back for His church, not willing that any should perish, but that all repent.

"The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance." - 2 Peter 3:9 KJV

"And the times of this ignorance God winked at; but now commandeth all men every where to repent [of their sins and turn to him]:" - Acts 17:30 KJV