Eschatology leads to holy, purposeful living. It leads us to flee from sin and pursue righteousness. It will keep us from worldliness. This is seen through-out the Bible. There are too many verses to list, but here are just a few.
1 John 2:28 "And now, little children, abide in Him, so that when He appears we may have confidence and not shrink from Him at His coming."
1 John 3:2-3 "Beloved we are God's children now and what we will be has not yet appeared; but we know that when He appears we shall be like Him, because we shall see Him as He is. And everyone who has this hope in Him purifies himself as He is pure."
2 Peter 3:11-14 "Since all these things are thus to be dissolved, what sort of people ought you to be in lives of holiness and godliness, waiting for and hastening the coming of the day of God, because of which the heavens will be set on fire and dissolved, and the heavenly bodies will melt as they burn!But according to His promise we are waiting for new heavens and a new earth in which righteousness dwells. Therefore, beloved since you are waiting for these, be diligent to be found by Him without spot or blemish and at peace."
Consider how the coming of the Lord Jesus will lead to holy living with this example. Suppose the parents of five children leave the house for a number of hours. They tell their children to behave and they will be back soon. Once the parents leave, chaos erupts in the house. Four children run around eating cookies and chips. They fight and leave a trail of destruction in the house. One child sits quietly and reads. The parents come home. What will happen? Discipline will be swiftly dealt out to four children, while one will be commended and praise. Read Matthew 24:45-51. Do you want a rebuke from our Lord when He comes? Do we want to be ashamed before His glorious face? Wouldn't we rather be commended by Him. So the coming of Jesus and other truths of eschatology will motivate us to holy living.
Clearly seeing by faith the return of the Lord, the destruction of the world, the new heavens and the new earth and eternity will change how we use our time, resources, gifts and energy. We will live with eternity in our eyes. We will live with a razor sharp focus. We won't be distracted by the cheap toys of this world. We won't live for our own petty kingdom or the kingdoms of this age. Our time, resources and gifts will be used for God's kingdom which will never pass away. We have eternity ahead of us. This life is so short. What will Jesus say to us at the end of our life? There is much work to be done in God's kingdom. Sinners are dying in their sins and going to hell. Who will go and tell them the good news? How many Christians are weak, immature, and undiscerning? They need to be taught the scriptures. They need to exhorted, rebuked, and encouraged. They need to be equipped to live lives that please God. Who will be as Apollos, a man mighty in the scriptures, to explain the word of God to them? The time for working for God's kingdom is now. Soon there will come a day when the time for working will be over. Soon will come a day when the day of salvation is over. Soon the day for judgement will come. Soon we shall stand before Christ and our life work will be tested and what is done for Christ's will remain. Then we shall receive our rewards. A deeper understanding of the things to come will help us to live with intense focus as we seek to make God's name great.