Wrong according Scripture.
You really ought to review all thing Luther and subsequent editors changed.
And when you accuse 'wrong according to scripture' you might try posting the supporting passages you hang yourself with.
For God so loved the world that He gave His only begotten Son, that whomsoever believeth in Him shall not perish but have everlasting Life. John 3:16
And again, when the 'leadership' of Judaism in His day asked Jesus what work God required for salvation, Jesus answered simply:
Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent. John 6:29
When Jesus asked the disciples whom the people said He is and then 'but whom say you that I AM', Peter's Holy Spirit inspired response is so true, so complete, so absolutely based upon God's Promise that Jesus expounded on the process to come (you know, the keys and the foundation rock):
And Simon Peter answered and said, Thou art the Christ, the Son of the living God. Matthew 16:16
And in his letters Paul echoed this same simple formula and not anything else:
That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. Roman 10:9
And Peter echoed this same simple Gospel when he preached in the home of Cornelius:
How God anointed Jesus of Nazareth with the Holy Ghost and with power: who went about doing good, and healing all that were oppressed of the devil; for God was with him. And we are witnesses of all things which he did both in the land of the Jews, and in Jerusalem; whom they slew and hanged on a tree: Him God raised up the third day, and shewed him openly ... And he commanded us to preach unto the people, and to testify that it is he which was ordained of God to be the Judge of quick and dead. To him give all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins. Acts 10:38 - 44
And we see how God affirmed this Gospel immediately, even before Peter finished his sermon!
While Peter yet spake these words, the Holy Ghost fell on all them which heard the word.
And that, dear Catholic is the Gospel of Salvation, complete, not needing anything else to be real and immediate. Believe that Jesus is the one God has sent for our Salvation, believe God has raised Him from the dead as your Savior, and you are then IN eternal life, by the Promise of God, not some man-made institution. Your eternal life with God begins with that utterance/confession of faith, because it is at that moment that God's Holy Spirit enters to indwell you and as far as you let, he changes you into what He finds 'comely'. For it is God Who is in you, both to will and do of His good pleasure, from the moment of your profession onward.