"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." (1 Corinthians 15:3-4)
This passage is often considered the defining passage of the gospel, stating the great truth that Christ died for our sins, then was buried (thus stressing that His resurrection was a physical resurrection, not just spiritual), and then rose again. As such, it is interesting that verse 1 which introduces it ("I declare unto you the gospel") contains the central mention of the more than 100 times the Greek word for "gospel" occurs in the New Testament.
However, it does not say why Christ died for our sins. It was not just to pay for our salvation and make us happy. There are, in fact, numerous references to His substitutionary death which do give us further insight into just why Christ died for us and our salvation.
For example, "he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again" (2 Corinthians 5:15). And consider Galatians 1:4, in which Paul tells us that Christ "gave himself for our sins, that he might deliver us from this present evil world."
Peter's testimony and explanation was that the Lord Jesus "his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness" (1 Peter 2:24). John said: "|God| loved us, and sent his Son to be the propitiation for our sins. Beloved, if God so loved us, we ought also to love one another" (1 John 4:10-11).
There are many other verses to the same affect. Christ did not die merely to save our souls, but to empower us to live in a way that would glorify God right here on Earth. HMM