Eschatology is the study of the “last things,” death, judgment, heaven, and hell, and we might say that eschatology provides both important knowledge and a focal point of sorts for Christian life and ministry. Let's explore that in more detail.
Eschatology provides critical knowledge about the end of human life. Christians believe that human beings are created for more than this world, and eschatology shows us this. Death came about as a result of sin, and now it touches every human being. Everyone must face death, and everyone must be prepared for what comes after it. Eschatology tells us about that as well, about the particular judgment that every person will face at death and the two eternal possibilities that follow, one if a person has remained in relationship with God and in God's grace and the other if a person has turned their back on God and chosen their own will.
Eschatology also provides something of a focal point for meditation and a goal for living. St. Paul speaks of running the race and winning the prize, of gaining eternal life with God (which is heaven). He is talking about eschatology and placing that eternal beatitude (seeing God face to face) at the very center of Christian life as the final goal, the perfection, of the rational creature that is a human being. With this goal clearly in mind, Christians are motivated to make good moral choices and live a life of love. They know that death will come and that they must be prepared to meet God at the judgment. No one is perfect, yet everyone has the chance to repent and obtain God's mercy before death. When people don't care to think about the last things, they often lose the sense of the necessity of repentance and mercy, and they may be unprepared for the judgment they will face.