O Thou mighty Lord, whose Son died on the Cross to redeem all the children of men, those who are near and those who are far off, I pray Thee to look with compassion upon the millions of my fellow men who are still sitting in the darkness and shadow of death, with immortal souls still lost, dead in trespasses and sin. Blinded they cannot find Thee. Dead, they cannot rise to newness of life. Grant that the missionaries may reach them with the message of the Cross that they may believe and live.
Wherever consecrated men and women are engaged in the blessed task of bringing the Gospel to the heathen, do Thou give success to their labors. Open the hearts of many to receive the saving Word of reconciliation. Establish Thy Church in the midst of the enemies, and let the fruits of true righteousness abound. Give Thy protection to all our missionaries abroad, and ward of all persecution. Keep them healthy and strong in body and mind. Give them the grace to be patient and faithful, and finally receive them and those whom they lead to Christ into the glory of heaven. I ask it in his name. Amen.
Taken from The Lutheran Book of Prayer, 1951
Local Evangelism and Frontier Missions by John Piper
Great explanation by Piper on the difference between local evangelism and frontier missions… and why we need both.