"Moreover, brethren, I declare unto you the Gospel which I preached unto you, which also ye have received, and wherein ye stand; by which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the Scriptures; and that He was buried, and that He rose again the third day according to the Scriptures: (and there are many witnesses) and that He was seen of Cephas, then of the twelve: after that, He was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep" (1 Cor. 15:1-6).
The Apostle John confirmed the saving power of the Gospel as well; he wrote: "And He is the propitiation (the satisfaction of the payment necessary) for our sins: and not for ours only, but also for the sins of the whole world" (1 Jn. 2:2). And again, he wrote: "Herein is love, not that we loved God, but that (God) loved us, and sent His Son to be the propitiation for our sins" (1 Jn. 4:10).
Some of you may have noticed that the word "repentance" does not appear in any of the quoted verses above, and you would be correct. However, let's look at what IS said: Jesus died for our sins; "...He hath made Him to be sin for us, Who knew no sin; that we might be made the righteousness of God in Him." (2 Cor. 5:21)! Knowing that, and believing that, has to result in repentance (a desire to turn from sin, and serve God)!
The Gospel of Luke demands that repentance be preached WITH the Gospel; Luke wrote:
"Then (Jesus) opened their understanding, that they might understand the Scriptures, and said unto them, Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day: and that REPENTANCE AND REMISSION OF SINS ("remission" means the forgiveness or pardon of sin) should be preached in his name among all nations, beginning at Jerusalem" (Lk. 24:45-47). And in 2 Corinthians 7:10, Paul wrote: "For GODLY SORROW WORKETH REPENTANCE TO SALVATION not to be repented of: but the sorrow of the world worketh death." The perfect example of the wrong kind of repentance is seen in the repentance of Judas (Mt. 27:3-5)!
JESUS DIE FOR YOU - IF YOU TRULY BELIEVE IT, LIVE FOR HIM!