This is the briefest summary of the New Testament that I can make.
For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. – John 3:16
Jesus was the Son of God, born into the world. He performed miracles of healing and deliverance. Some people believed in Him, and some didn’t. Some did and then didn’t and some didn’t and then did. Those who didn’t believe conspired against Him and had Him tortured and executed. But what they didn’t know is that death was a death that paid for all of our sins and and three days later He rose from the dead restoring life to us all. Eternal life. Some of those who followed Him began to spread the word about Him and became the Catholic Church.
Peace be with you.