To his most reverend brother and fellow-bishop Boniface, Gregory, the servant of the servants of God.
Moved by our anxiety for the charge committed to us and by the words of the Gospel, which says, “You must ask the lord to whom the harvest belongs to send labourers out to the harvesting”, we sent you just as the Lord sent the Apostles with the command: “Go out all over the world and preach the Gospel: freely you have received, freely give.”
We sent you to shed some light on the people of Germany who sit in the shadow of death, so that, like the servant with the single talent, you might make some profit for God. And as we see that through your obedience the ministry of the Word has succeeded  and, as we hear, by your preaching great numbers have been converted to the faith, we give thanks to God that He from whom all good proceeds and whose win it is that all men should be led to recognize the truth, should second your efforts and bring this people by His powerful inspiration from darkness to light.
For this reason we believe that a bountiful reward is laid up by Almighty God for us in heaven. If you are steadfast, you will be able to say with the Apostle: ” I have fought the good fight, I have finished the race, I have redeemed my pledge.” To gain the prize, you must persevere, for God promises it only to those who are steadfast to the end.
Do not be frightened by threats or discouraged by fears. Keep your trust fixed on God and proclaim the word of truth. Provided your will is constant in good works, God win crown it by His help. Therefore, the more people you convert from the errors of their ways (and that this is so we know from your letter), the more we shall rejoice and thank God for the gaining of souls.
As for the bishop who was too lazy to preach the Word of God and now claims a part of your diocese, we have written to our son, Duke Charles, asking him to restrain him, and we believe that he will put a stop to it. For your part, however, continue to preach in season and out of season.
We have written to the people of Thuringia and Germany regarding matters which concern their spiritual welfare, ordering them among other things to erect bishoprics and build churches. For He who desires not the death of the sinner but his conversion win grant an increase in everything.
May God preserve you.