What does the seafarer say about salvation—that is, what message about salvation does the text give, and what techniques are used to achieve this?

"The Seafarer" is an elegy in the Anglo-Saxon tradition and focuses mainly on the theme of exile. Its protagonist, the seafarer himself, speaks of having been "fettered" by the cold of the sea when he had only ylfete song (the song of the wild swans) to lift his spirits, because he was kept away from the laughter of his companions and the buzz of the mead hall. Like all Anglo-Saxon exiles, the seafarer is lamenting that he has been forced to wander hwæles eþel—"the whale's abode," a kenning referring to the sea—and is therefore alone.
However, this extreme pain has caused the seafarer to yearn for his spirit to be able to journey beyond the earth and escape the pain which has been visited upon him by dryhten, the Lord.
Toward the end of the poem, the seafarer begins to speak of dryhtnes dreamas, the joys of the Lord, for which his spirit now yearns. Of salvation, he says that it is far more important to have joy among the heavenly host than on Earth, where the riches are transitory and will pass away. However, he does also state that it is to the benefit of the living to ensure they have a good reputation in life, so that their children will speak well of them afterwards, which will ensure them a good place among the angels. Perhaps the poem's most significant comment on salvation is this:

ne mæg þære sawle þe biþ synna fulgold to geoce for godes egsan
"Gold cannot be any help to a soul that is full of sin before the terror of God."

There is no value in hoarding gold while living, or burying gold with the dead, for these are not the means by which salvation will be achieved. Instead:

Dol biþ se þe him his dryhten ne ondrædeþ; cymeð him se deað unþinged.Eadig bið se þe eaþmod leofaþ; cymeð him seo ar of heofonum
"He who does not fear the Lord is foolish, because death will come to him unprepared. He who lives humbly will receive grace from the heavens."

I have included the Anglo-Saxon text specifically so that you can see the parallelism in the two phrases, which emphasizes the difference between these two states using the anaphora of "cymeð him."
In order to reach God, then, we must consider how we intend to reach him through our behavior on earth. We should consider this long before death comes to us, so that we may live blessedly with God. The seafarer's ponderings on God use various stock "gnomic," or wise, phrases to emphasize this fact toward the end of the poem.