Although John Wycliffe’s 1382 English translation of the Bible is likely the first translation into the language of the people since the fall of the Roman Empire, the Catholic Church thoroughly suppressed his work, and his translation was forgotten by the time of the Reformation.
Much later, in the 16th Century, Martin Luther translated the scriptures into German, and thus lit a fire under the Protestant Reformation. Soon, William Tyndale translated the Bible into English, and although he was burned at the stake for doing so, the church authorities were unable to keep translations out of the hands of the people. Soon the church was publishing its own translation (one of which is now called the King James Version).
Famously, Luther translated Rom 3:28 by adding “alone” after “faith” (in German, of course) –
(Rom. 3:28 ESV) For we hold that one is justified by faith [alone] apart from works of the law.
The argument has often been made that Luther’s translation led to centuries of doctrinal error. However, Calvin and Zwingli developed their theology from their own Bibles – the Latin Vulgate or Erasmus’s Greek text – not Luther’s German translation. Tyndale did not add “alone” to his translation, nor is it in the KJV.
The Baptist teaching that one is saved when he first comes to faith, not baptism, traces back to the Reformed Church founded by Calvin and Zwingli, not back to Luther. In fact, Luther insisted on baptism as the moment of salvation.
This is from his Large Catechism –
For it is of the greatest importance that we esteem Baptism excellent, glorious, and exalted, for which we contend and fight chiefly, because the world is now so full of sects clamoring that Baptism is an external thing, and that external things are of no benefit. But let it be ever so much an external thing, here stand God’s Word and command which institute, establish, and confirm Baptism. But what God institutes and commands cannot be a vain, but must be a most precious thing, though in appearance it were of less value than a straw. …
Still Baptism is itself a work, and you say works are of no avail for salvation; what, then, becomes of faith? Answer: Yes, our works, indeed, avail nothing for salvation; Baptism, however, is not our work, but God’s (for, as was stated, you must put Christ-baptism far away from a bath-keeper’s baptism). God’s works, however, are saving and necessary for salvation, and do not exclude, but demand, faith; for without faith they could not be apprehended. For by suffering the water to be poured upon you, you have not yet received Baptism in such a manner that it benefits you anything; but it becomes beneficial to you if you have yourself baptized with the thought that this is according to God’s command and ordinance, and besides in God’s name, in order that you may receive in the water the promised salvation. Now, this the fist cannot do, nor the body; but the heart must believe it.
Thus you see plainly that [baptism] is here no work done by us, but a treasure which He gives us, and which faith apprehends; just as the Lord Jesus Christ upon the cross is not a work, but a treasure comprehended in the Word, and offered to us and received by faith. Therefore they do us violence by exclaiming against us as though we preach against faith; while we alone insist upon it as being of such necessity that without it nothing can be received nor enjoyed.
It’s a shame that so many in the Churches of Christ have treated Luther as the enemy of our baptismal theology. In fact, he may be the greatest defender of the necessity of baptism born since the apostolic age.
 Martin Luther, Large Catechism, “Holy Baptism” (1538), published in Triglot Concordia: The Symbolical Books of the Evangelical Lutheran Church: German-Latin-English (St. Louis: Concordia Publishing House, 1921).