Scripture verses that summarize the Gospel are sprinkled throughout the Bible.  Here are some cited by JI Packer in the book, Grounded in the Gospel:

• He was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was upon him, and by his wounds we are healed (Isa. 53:5)
• For even the Son of Man did not come to be served, but to serve, and give his life as a ransom for many (Mark 10:45)
• God so loved the world that he gave his one and only Son, that whoever believes in him should not perish but have eternal life (John 3:16)
• All the prophets testify about him that everyone who believes in him receives forgiveness of sins through his name (Acts 10:43)
• Through Jesus the forgiveness of sins is proclaimed to you. Through him everyone who believes is justified from everything you could not be justified from by the Law of Moses (Acts 13:38-39)
• He was delivered over to death for our sins and was raised to life for our justification (Rom. 4:25)
• But God demonstrates his own love for us in this: while we were still sinners, Christ died for us (Rom. 5:8)
• Christ died for our sins, according to the Scriptures … he was buried. . . . The third day he rose again from the dead, according to the Scriptures . . . and he appeared (1 Cor. 15:3-6). Paul writes that this is the Gospel “I preached to you, which you received and on which you have taken your stand. By this Gospel you are saved” (1 Cor. 15:1-2). In outlining it here, Paul asserts that “what I received I passed on to you is of first importance” (1 Cor. 15:3)
• God was in Christ, reconciling the world to himself, not counting men’s trespasses against them (2 Cor. 5:19)
• God made him who knew no sin to be sin for us, that we might become the righteousness of God in him (2 Cor. 5:21)
• Remember Jesus Christ, raised from the dead, descended from David: this is my Gospel (2 Tim. 2:8)
• He gave himself for us to redeem us from all wickedness and to purify for himself a people that are his very own, eager to do what is good (Titus 2:14)
• But when the goodness and loving kindness of God our Savior appeared, he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit, whom he poured out on us richly through Jesus Christ our Savior, so that being justified by his grace we might become heirs according to the hope of eternal life. (Titus 3:4-7)
  
• Christ was sacrificed once to take away the sins of many people; and will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him (Heb. 9:28)
• He himself bore our sins in his body on the tree, so that we might die to sins and live for righteousness; by his wounds you have been healed  (Peter 2:24)
• Christ died for sins once for all, the righteous for the unrighteous, to bring you to God (1 Peter 3:18)
• This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins (1 John 4:10)

Follow these links to learn more about the Gospel, answer the question “Am I a good person” and see a contrast between the true and false Gospel

Bible Verses about Obedience will help you understand why we must follow God’s will