[1][2] J. G. Oncken helped direct and guide the growth of Baptists throughout Germany and across much of Europe for half a century.

By 1823 Oncken had returned to Germany as an agent of the British Continental society for the Diffusion of Religious Knowledge over the Continent of Europe.

Though Oncken lived in Scotland and was converted in London, there is no existing evidence of any contact with the English Baptists.

By 1829, though still a member of a church that taught infant baptism, he appears to have decided against it, for in that year he refused to present his child for the ceremony.

Sears traveled from Halle, where he was studying, to Hamburg, and baptized Oncken, his wife and five others in the Elbe on 22 April.

Though the Baptists initially engaged in performing baptisms at night, in 1837 Oncken began to baptize openly.

That year, he baptized fellow German Baptist pioneer Gottfried Wilhelm Lehmann on Pentecost Sunday.

[7] German authorities shared the traditional Christian opposition to rebaptism; they also felt that people being dipped in the river was an offence to public morals.

In 1848, Oncken was involved in founding Das Missionblatt, the first Baptist paper published regularly in Europe.

[9] While in Hamburg, Oncken became acquainted with Jacob Gysbert van der Smissen, a Mennonite deacon.

Köbner preached the funeral sermon from Psalm 73:24, "Thou shalt guide me with Thy counsel, and afterwards receive me to glory."

Two verses of Scripture were placed on his grave: "One Lord, one faith, one baptism" (Ephesians 4:5), and "And they continued steadfastly in the apostles' doctrine and fellowship, and in breaking of bread and in prayers" (Acts 2:42).

J. G. Oncken was truly an international man—converted in England, baptized by an American in Germany, he traveled across the European continent to preach the gospel and give out Bibles.

He conducted "preaching tours" in the Balkans, France, Hungary, Prussia, Russia, and Switzerland, as well as visiting Britain and the United States.

He was born a Lutheran, was converted at a Methodist meeting, adopted Baptist views and possessed a relationship with the Mennonites.

God does not convert the sinner, to show to him how good he is, but how weak, helpless, sinful and depraved he is, that thus all self-dependence may be destroyed.

But then the Spirit of Christ who teaches us this bitter lesson concerning ourselves, also shows us from the Holy Scriptures what a gracious, faithful and almighty Saviour we have, and that through the grace and strength of Him we can do all things.

The two great truths which from the day of our conversion to the day we enter into heaven the Lord teaches those who shall be saved are in reference to ourselves that we are poor, lost, helpless sinners, who, if left to themselves, must perish for ever, and in reference to God, that out of boundless compassion He has sent His only begotten Son into the world to atone for the guilt of all who should believe in Him, and then in this glorious Saviour more – infinitely more – has been brought back to all who believe in Him, than ever was lost by Adam's transgression and our own sin.J.