“This is eternal life: that they may know you, the only true God, and the one you have sent — Jesus Christ.” John 17:3 CSB https://bible.com/bible/1713/jhn.17.3.CSB

The work of God is to believe in Jesus (Jn6). Eternal life is to know Jesus; in knowing Jesus, we know God. Eternal life, heaven, and salvation are a relationship. We gain eternity by having a relationship with God through His Son, God as man, Jesus, the Savior of the world. We do not work by doing good to get to heaven, for we cannot do more good than the evil we are. From birth, we are corrupt. Our nature is rebellious against God and man and cannot be redeemed by us doing what we think is more good than bad. We are merely trying to do less bad, but that will not earn us heaven. We must be perfect, and none of us are, nor can we be. A perfect God must require perfection; otherwise, He wouldn’t be perfect, and if God is not perfect, then is He truly God? But God is perfect, so He came to earth as man to live perfectly before man so that He could exchange with man His perfection, taking upon Himself our imperfection and being punished for it by dying on the cross. He has become the Savior Who alone can pardon men for their imperfections. We must believe and follow Jesus as Lord and Savior to be pardoned. By believing, we obey Him, following in His footsteps, and doing the work He did on earth. Not dying on a cross for humanity but sharing His death on the cross with humanity so that everyone can believe and be reconciled to God. If we know Him, we will love Him, and if we love Him, we will obey Him, and if we obey Him, we will share Him with others.