Who: God, Jesus Christ and the Holy Spirit
When: From the beginning
Why: God created the world and all in it, as well as “people”. They lived in paradise, Garden of Eden. They had no knowledge of Good and Bad. But evil tempted them. But man sinned and this meant that death would be a part of life, instead of eternal life as God intendend it to be. To change this situation back, someone had to pay the debt for the sins of all humans.
How: So God sent his son, Jesus Christ to earth, to live amoung us. But he had a task; to pay for all sins by being crucified. But he raised back to life 3 days later. This is the moment that death was defeated. If you believe and confess that Jesus did die for you, and if Gods mercy is given the ORIGINGAL eternal life is given back. In the end, a new Heaven on Earth will be created.
Actions: You can NOT do anything to deserve this mercy, it is given. Although you need to OPEN THE DOOR to allow God to come in. This is the CHOICE you have to make.