1 Peter 1

As the head, prophet, or president of the Church of Jesus Christ, Peter knew the great challenges, tribulations, and persecutions that the saints were being confronted with and would increase, first reminds them that they are the -

"Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ..."  (New Testament | 1 Peter 1:2)

Of this election, the Prophet Joseph Smith taught -

"Every man who has a calling to minister to the inhabitants of the world was ordained to that very purpose in the Grand Council of heaven before this world was. I suppose I was ordained to this very office in that Grand Council."  (Teachings of the Prophet Joseph Smith, p. 365.)

Election does not only take place in the pre-mortal existence.  Elder Bruce R. McConkie wrote -

"To bring to pass the salvation of the greatest possible number of his spirit children, the Lord, in general, sends the most righteous and worthy spirits to earth through the lineage of Abraham and Jacob. This course is a manifestation of his grace or in other words his love, mercy, and condescension toward his children. This election to a chosen lineage is based on preexistent worthiness and is thus made ‘according to the foreknowledge of God.’ (1 Pet. 1: 2.) Those so grouped together during their mortal probation have more abundant opportunities to make and keep the covenants of salvation, a right which they earned by preexistent devotion to the cause of righteousness. As part of this election, Abraham and others of the noble and great spirits were chosen before they were born for the particular missions assigned them in this life.…( Abraham 3: 22– 24; Rom. 9.) Actually, if the full blessings of salvation are to follow, the doctrine of election must operate twice. First, righteous spirits are elected or chosen to come to mortality as heirs of special blessings. Then, they must be called and elected again in this life, an occurrence which takes place when they join the true Church. (D& C 53: 1.) Finally, in order to reap eternal salvation, they must press forward in obedient devotion to the truth until they make their ‘calling and election sure’ (2 Pet. 1), that is, are ‘sealed up unto eternal life.’ (D& C 131: 5.)"  (McConkie, Mormon Doctrine, pp. 216– 17.)

With these tribulations that would come, Peter counsels -

"Wherein ye greatly rejoice, though now for a season, if need be, ye are in heaviness through manifold temptations:
7 That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ..."  (New Testament | 1 Peter 1:6 - 7)

"Receiving the end of your faith, even the salvation of your souls."  (New Testament | 1 Peter 1:9)

In my mind, Peter is pleading that the saints remain faithful and endure all this until the end that they may receive the promises -

"Of which salvation the prophets have enquired and searched diligently, who prophesied of the grace that should come unto you..."  (New Testament | 1 Peter 1:10)

For those that take Paul's comment that we are saved by faith only, listen to Peter, Paul's senior -

"Wherefore gird up the loins of your mind, be sober, and hope to the end for the grace that is to be brought unto you at the revelation of Jesus Christ;
14 As obedient children, not fashioning yourselves according to the former lusts in your ignorance:
15 But as he which hath called you is holy, so be ye holy in all manner of conversation;
16 Because it is written, Be ye holy; for I am holy."  (New Testament | 1 Peter 1:13 - 16)

"Conversation" is this case means conduct for -

"...the word of the Lord endureth for ever..."  (New Testament | 1 Peter 1:25)