It Is Well

In the way I see it, this is not a love song but a religious one, speaking about (3rd person) or to (2nd person) to God (Lord/Seigneur). So all the related words need higher key as in the original text. son voix -> Sa voix ( by the way, adjectif possessifs agrees with the possession, not possessor, unlike English). Sur toi -> sur Toi, sur Toi Seigneur, Son nom
As in other times, I suffer from the absence of punctuation. I took liberty to put periods (full stops) at:
primo, the 4th line : broken to my regard;
secondo, the 15th lỉn: into the midst of the sea
tertio, the 23rd line: and wind will know His name.
and a semi colon (point virgule ;) at the 2nd line.
A couple of missing accents on past participles happen (tremblé, déplacé secoué, cassé âme), I hope the translator’s keyboard doesn’t have this option.

The first English word “grander”- grammatically speaking – is a comparaison but to what? So I agree with Omer Kutay to come back to the normal state: gigantesque, grandiose. He picked the last one but mispelled into grandoise.
Le sol, of course, relates to the earth. But the word “sol” suggests a smaller scope, used in intimate cases: sol natal, sol aride, sol fertile for exemple. But “la terre” is both large and limited. It’s better to translate earth into terre or globe.
Before can stand alone to tell past times but French “avant” cannot. Avant l‘arrivée de l’avion; avant qu’il vienne. I would like to suggest a longer term “auparavant”.

Les mers que sont secoue et agite
Peux etre calme et casse pour mon regarde
Here is my wording:
Les mers qui sont secouées et agitées
Peuvent être calmées ou cassées sous mes regardes.

Travers is a noun (quirk, side). “À travers” will help.

Far be it from me to not believe
Even when my eyes can't see
And this mountain that's in front of me
Will be thrown into the midst of the sea

Loin etre cela a partit de moi de ne pas croire
Meme quand mes yeux ne peuvent pas voir
Et cette montagne c'est devant moi
Seront jetes dans le milieu de la mer

This is mine:
Au loin soit-elle, inimaginablement,
Même quand mes yeux ne puissent pas la voir,
Cette montagne qui se tient devant moi
Sera jetée au milieu de la mer [ “en pleine mer”].

I mean: though being far away, beyond my believe, beyond my imagination, even in case that I ncould not see it, this moutain which stands right in front of me will be thrown into the center of the seas. Au loin soit-elle <- quoiqu’elle soit au loin de moi; [after quoique, malgré que, verbs are to be at subjonctif (soit, être). In this suggestion, “elle” and “la” stand for the montagne.

So let go my soul and trust in Him
The waves and wind still know His name
Si lacher mon ame et confiance en lui
Les vagues et le vent encore connaissent son nom.

If “let go my soul” can be understood in Oriental way, don’t let your spirit to be darkened, tangled with odd thoughts, forget it, drop off the mind, to trust Him; the like of winds and wave simply knowing His name. The English text is ambiguous. Based on grammatical structure, this is an advice, an order, a request – imperative mood: could you please let go ..and trust. OK but you let go your soul, you can not let go mine.

Just in case of your soul, I would say:

Donc, lâche ton âme et fais confiance en Lui,
de même que les vagues et le vent En connaissent le nom.