This is not true. There is not a book in the Bible that is written to the unsaved. Matthew is written to Christians, albeit Christians having a Jewish background.Matthew was written to Jews, not Christians.
Salvation by grace through faith is always in view.Salvation by grace through faith was not yet in view.
God uses the same method of salvation in the Bible from Genesis through Revelation. We are justified by faith. And that is His grace.
Tell me a man that was never justified by faith and still went to heaven.
The gospel writers wrote with those various audiences in mind. But they were still written to Christians.Jesus came as the promised Jewish Messiah to save that which was lost, Israel. Mark was written to Romans in Rome. He explains Matthew to non-Jews, but does not apply it to Gentiles. It is the same with Luke, written to Greeks and Hellenistic Jews. Explanation, not application, in Mark and Luke. Those Jews who accepted Jesus as Messiah and were ritually bathed were restored to the Covenants. Those who did not were condemned.
The Jews had many ceremonial "washings," but no baptism per se.Water baptism was required under Judaism;
That depends on your definition of "baptism by the Holy Spirit."it is not required for Christians, who are baptized in and by the Holy Spirit at the precise split-second of expressing belief in Jesus as Savior by grace through faith.
It also depends on your view of soteriology.
Timothy was raised in the Jewish faith, not the Christian faith. Not until Paul came along on one of his missionary journey's did he come to the Lord. His mother and grandmother were devout Jews; but his father was a Greek. Paul went and circumcised Timothy so that he would be able to enter the Temple, and be of more use in the ministry. He had a Jewish heritage.What does Paul cause to be written in 1 Timothy 4:6-10? "You’ve been raised on the Good News of the Faith and have followed sound teaching. Now pass on this counsel to the followers of Jesus there, and you’ll be a good servant of Him." (DET).
Now 15:16: "The people will all see you mature right before their eyes! Keep a firm grasp on both your status and your teaching. Don’t be diverted. Just keep at it. Both you and those who hear you will experience salvation." (DET).
Obviously Timothy is already in the faith and he is preaching to & teaching Christians. For them to "experience salvation" is NOT conditional! It is present tense, and therefore is obviously a promise.
Timothy made a one time decision when Paul confronted him with the Gospel. Paul often refers to Timothy as "my child in the faith," for that reason.