He Himself is the propitiation for our sins, and not for ours only but also for the whole world —1 John 2:2
The key to the missionary’s message is the propitiation of Christ Jesus— His sacrifice for us that completely satisfied the wrath of God. Look at any other aspect of Christ’s work, whether it is healing, saving, or sanctifying, and you will see that there is nothing limitless about those. But— “The Lamb of God who takes away the sin of the world!”— that is limitless (John 1:29). The missionary’s message is the limitless importance of Jesus Christ as the propitiation for our sins, and a missionary is someone who is immersed in the truth of that revelation.
The real key to the missionary’s message is the “remissionary” aspect of Christ’s life, not His kindness, His goodness, or even His revealing of the fatherhood of God to us. “. . . repentance and remission of sins should be preached . . . to all nations . . .” (Luke 24:47). The greatest message of limitless importance is that “He Himself is the propitiation for our sins . . . .” The missionary’s message is not nationalistic, favoring nations or individuals; it is “for the whole world.” When the Holy Spirit comes into me, He does not consider my partialities or preferences; He simply brings me into oneness with the Lord Jesus.
A missionary is someone who is bound by marriage to the stated mission and purpose of his Lord and Master. He is not to proclaim his own point of view, but is only to proclaim “the Lamb of God.” It is easier to belong to a faction that simply tells what Jesus Christ has done for me, and easier to become a devotee of divine healing, or of a special type of sanctification, or of the baptism of the Holy Spirit. But Paul did not say, “Woe is me if I do not preach what Christ has done for me,” but, “. . . woe is me if I do not preach the gospel!” (1 Corinthians 9:16). And this is the gospel— “the Lamb of God who takes away the sin of the world!”
Oswald Chambers, My Utmost For His Highest