How Firm a Foundation?

I have been listening to YouTube for a while and I heard Dr. Robert Sala quote the following poem/hymn written by Robert Keen in Europe around 1787. I am greatly touched by its message.

1. How firm a foundation ye saints of the Lord,
Is laid for your faith in his excellent word;
What more can he say than to you he hath said?
You, who unto Jesus, for refuge have fled.

2. In ev'ry condition - in sickness in health,
In poverty's vale, or abounding in wealth,
At home and abroad, on the land, on the sea,
As thy days may demand, so thy succor shall be.

3. “Fear not, I am with thee; O be not dismayed!
For I am thy God, and will still give thee aid;
I'll strengthen thee, help thee, and cause thee to stand,
Upheld by my righteous, omnipotent hand.

4. “When through the deep waters I call thee to go,
The rivers of sorrow shall not thee o'erflow;
For I will be with thee, thy troubles to bless,
And sanctify to thee thy deepest distress.

5. “When through fiery trials thy pathway shall lie,
My grace all-sufficient shall be thy supply;
The flame shall not hurt thee; I only design,
Thy dross to consume, and thy gold to refine.

6. “E'en down to old age, all my people shall prove
My sov'reign eternal, unchangeable love;
And then, when grey hairs shall their temples adorn,
Like lambs they shall still in my bosom be borne.

7. “The soul that on Jesus hath leaned for repose,
I will not, I cannot, desert to his foes:
That soul, though all hell should endeavor to shake,
I'll never - no, never, no, never forsake!”

In the Jewish New Testment, 1 Corinthians 15:58, Sh'aul writes, verse 58) "So, my dear brothers, stand firm and unmovable, always doing the Lord's work as vigourously as you can knowing that united with the Lord your efforts are not in vain."

Also in 2 Timothy 4:5, "But you, remain steady in every situation, enduring suffering, do the work that a proclaimer of the Good News should and do everything your service to God requires."