III) The Gospel -
What is it?
The good news is that:
•    The one and only God who is holy made us in his image to know him (Gen. 1:26-28).
•    But we sinned and cut ourselves off from him (Gen. 3; Rom. 3:23).
•    In his great love, God became a man in Jesus, lived a perfect life, and died on the cross, thus fulfilling the law himself and taking on himself the punishment for the sins of all those who would ever turn from their sin and trust in him (John 1:14; Heb. 7:26; Rom. 3:21-26, 5:12-21).
•    He rose again from the dead, showing that God accepted Christ’s sacrifice and that God’s wrath against us had been exhausted (Acts 2:24, Rom. 4:25).
•    He now calls us to repent of our sins and trust in Christ alone for our forgiveness (Acts 17:30, John 1:12). If we repent of our sins and trust in Christ, we are born again into a new life, an eternal life with God (John 3:16).

[Notice that Jn 1:12 & Jn 3:16 do not contain or imply repent of ones sins in the sense of not committing them? The operative word is "believe" and believe alone: A moment of faith alone in Christ alone + nothing else!!
A) [Compare John 1:12-13]:
(Jn 1:12 NASB) "But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name,
(Jn 1:13 NASB) who were born, not of blood nor of the will of the flesh nor of the will of man, but of God."
B) [Compare Acts 17:30-31]: 
(Acts 17:30 NASB) "Therefore having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent,
(Acts 17:31 NASB) 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."
Acts 17:30 has 16 chapters before it which fully establishes that the repent in view is a change of mind from not believing to believing in Christ alone for forgiveness of sins and nothing else.
For example:
C) [Acts 10:43]:
(Acts 10:43 NASB) "Of Him all the prophets bear witness that through His name everyone who believes in Him receives forgiveness of sins."
D) [Compare Acts 16:30-31]:
(Acts 16:30 NASB) "And he [the keeper of the prison, (v. 27)] brought them out and said, 'Sirs, what must I do to be saved?'
(Acts 16:31 NASB) 'Believe on the Lord Jesus Christ, and you will be saved' "
So where is the concept of repent / turning from committing sins to not committing sins? NO WHERE!!!
For other passages in Acts and elsewhere in the Bible refer to a change of mind from not believing to believing unto eternal life as evidence in the examination of the word repent linked below which is an absolute essential for the believer to master if he is to be qualified to share the gospel of eternal life: 

REPENTANCE AS DEFINED IN GOD'S WORD

I) THE GREEK WORDS METANOEO (VERB) AND METANOIA (NOUN) RENDERED "TO REPENT" AND "REPENTANCE" MEAN A CHANGE OF THE MIND. THEY DO NOT INCLUDE OTHER SPHERES OF ACTIVITY OUTSIDE OF THE MIND, SUCH AS A CHANGE OF BEHAVIOR, WITHOUT OTHER WORDS PRESENT IN THE TEXT AT HAND TO DESIGNATE THIS

The Greek words metanoeo (verb) and metanoia (noun) rendered to repent and repentance come from the combination of the Greek words meta meaning 'after', implying change and the Greek word noeo meaning the mind. They literally mean an 'after thought,' in the sense of a rethinking. The implication here is a change of mind - a change in the direction of thought - from one thing to another which things are mutually exclusive from one another. Furthermore, the sphere of this word is limited to within the mind. Other spheres of activity such as a change of behavior are not in view relative to the word repent, as some contend. These other activities require other words to be present in the text at hand which designate changes outside of the sphere of the mind.

A) [Compare 2 Tim 2:24-25]:

(2 Tim 2:24 NKJV) "And a servant of the LORD must not quarrel but be gentle to all, able to teach, patient,

(2 Tim 2:25 NKJV) in humility correcting those who are in opposition, if God perhaps will grant them repentance, so that they may know the truth."

(v. 25) Those who oppose him he must gently instruct, in the hope that God will grant them repentance [metanoian] leading them to a knowledge of the truth."

Notice that author Paul indicates that a servant of the Lord, a pastor/teacher is to gently instruct in the Word of God, (v. 4:2), those who oppose him in the hope that God will grant them repentance, i.e., a change of mind which leads to a knowledge, i.e., an acceptance, belief in the truth of God's Word being taught. So repentance = metanoian here is not a feeling of regret, or an action of some kind, but simply a change of mind from opposing, i.e., rejecting or disbelieving truths from God's Word to a knowledge and acceptance of them, i.e., belief in them. From disbelief to belief. When one believes in a statement which is taught in Scripture, one turns from doubt or unbelief to faith in that statement.

II) REPENTANCE RELATIVE TO FORGIVENESS OF SINS UNTO ETERNAL LIFE IN THE ETERNAL KINGDOM OF GOD MEANS TO CHANGE THE MIND - TO TURN FROM A BELIEF SYSTEM WHICH IS NOT SOLELY IN CHRIST ALONE TO ONE WHICH IS