Protestants believe in Five Solas for how salvation is attained:
- Sola Fide, by faith alone.
To teach that besides faith in Christ other devices like works, or the
observance of rules, traditions, or ceremonies are necessary for the
attainment of righteousness and everlasting life, is to make Christ and His
salvation of no benefit to anybody. 1
- Sola Scriptura, by Scripture alone.
What is asserted without the Scriptures or proven revelation may be held as an opinion, but need not be believed.2
- Solus Christus, through Christ alone.
A new creature is one in whom the image of God has been renewed. Such
a creature cannot be brought into life by good works, but by Christ alone. 3
- Sola Gratia, by grace alone.
teaches that we must be saved solely by the grace of God 4
- Soli Deo Gloria, glory to God alone.
So, whether you eat or drink, or whatever you do, do all to the glory of God.5
So no action, ritual, or thing that you do helps because God's grace doesn't depend on our works. Some Protestants believe once you're saved there is nothing you can do to jeopardize your salvation. Others believe it is possible to lose it.
The LDS believe there are two parts of salvation:
For a more in-depth response to LDS belief on salvation refer to this answer.
The difference is that Protestants don't believe anything a man does matters as long as he follows the five solas (faith, scripture, Christ, grace, and glory to God alone) he is saved. The LDS believe that if you have faith you will repent, be baptized, receive the Holy Ghost, and endure to the end; then you will be saved by grace.
All emphasis was added
1 http://www.online-literature.com/martin-luther/epistle-to-the-galatians/5/, Ephesians 2:8
2 http://www.christianitytoday.com/history/issues/issue-34/dr-luthers-theology.html, Romans 15:4, 2 Timothy 2:16
3 http://www.online-literature.com/martin-luther/epistle-to-the-galatians/6/, Acts 4:12, Hebrews 7:25, Romans 8:34
4 https://reformedreader.wordpress.com/2011/03/15/luther-on-grace-alone-sola-gratia/, Ephesians 2:8
6 https://www.lds.org/topics/salvation?lang=eng&old=true, 1 Corinthians 15:22
7 Acts 2:37-38, 2 Peter 2:20-22, John 3:5