This is a fallacy of the antecedent, where the answer to “What must I do to be saved?” is appended with some form of “and accept Jesus as your Lord and Savior, or some derivative of the sentiment.
This question was answered in Acts 16:31:
“..Believe on the Lord Jesus Christ, and thou shalt be saved…”
That’s it. The Bible is plain and meant to be understood by the simplest of minds—no advanced degree required. However, there are people who push this “AND” fallacy and complicate a very simple principle. There’s a dew-moist and moss-laden path consisting of “works” that need to be done at the end of this particular heresy.
From fortheloveofhistruth.com:
Those who embrace the teaching of Lordship Salvation would disagree and convey that a person must promise to follow Christ, obey Him, and make Christ Lord over area of his life before he can be saved. Lordship Salvation teaches there is a price or cost that is attached to salvation. In short, a person must meet the requirements for discipleship, become a follower of Christ, commit himself totally to Christ, step out to obey His commands, make Jesus Lord over area of his life, take the initiative to serve Christ, and comply with the conditions that Jesus requires for salvation, ___if___* he wants to be saved.
Lordship Salvation is a serious departure from the historic and Biblical teachings regarding the content of the Gospel message, old-fashion repentance, and simple faith in Christ. When this teaching is analyzed in the light of God’s Word it is found to be spurious and misleading. Lordship Salvation pertains to the area of a person’s salvation and specifically how a person is saved. For this reason it becomes a serious issue in relationship to what a person must do in order to be saved. It strikes at the very heart of the orthodox Christian faith.
FOOTNOTE *: Emphasis mine, here.
