Many laborers in the harvest have been working for 20, 30, or 40+ years, sowing seeds of the gospel. (How did we get this old?) We don’t plan to retire, but to serve Christ, “til we drop” (to quote John Piper). As Paul trained Timothy, we know that part of our job is to teach and train the younger generation to carry on after us. So multitasking becomes part of our repertoire. As we sow the good seed out to many through evangelism, we pour ourselves into a few through discipleship.
How is this done? Find a young believer, and teach them everything you have learned. Take them with you when you go out witnessing. Teach from the Bible, and teach by modeling and mentoring. Pour yourself into them. If you are a parent with children or young teens, your job is to pass on the faith. Just teach the Bible and talk about everything. You could try adding a little Worldview and Apologetics. There is also Church History and Christian biography to inspire and challenge them. Teach them something of the persecuted church around the world, to give them some perspective.
No matter where we are in relation to the “end of the age” (Matt.28:20), when our work is done and the Lord calls us home, we will be leaving behind the younger generation. It will then be their turn to give testimony of the gospel of Jesus Christ and witness of the Word of God.
O God, Thou hast taught me from my youth; and I still declare Thy wondrous deeds. And even when I am old and grey, O God, do not forsake me until I declare Thy strength to this generation, Thy power to all who are to come. Ps. 71:17-18