Final answer:
The New Testament writer who really cared about heaven was the apostle Paul. Paul emphasized the importance of eternal life in heaven.
Step-by-step explanation:
The New Testament writer who really cared about HEAVEN was the apostle Paul. Paul played a significant role in popularizing the notion that Jesus's death on the cross was part of a divine plan that canceled out human sin. He often emphasized the importance of eternal life in heaven and encouraged believers to focus on heavenly rewards rather than earthly concerns.