His providences may change, His heart cannot.

(Octavius Winslow, "Morning Thoughts")

"I am the Lord, and I do not change. That is
 why you descendants of Jacob are not already
 completely destroyed." Malachi 3:6

The immutability of God forms a stable foundation
of comfort for the believing soul. Mutability marks
everything outside of God.
Look . . .
  into the church,
  into the world,
  into our families,
  into ourselves,
what innumerable changes do we see on every hand!
A week, one short day, what alterations does it
produce! Yet, in the midst of it all, to repose calmly
on the unchangeableness, the faithfulness of God.

To know that no alterations of time, no earthly changes,
affect His faithfulness to His people. And more than this;
no changes in them, no unfaithfulness of theirs, causes
the slightest change in God. Once a Father, always a
Father; once a Friend, always a Friend.

His providences may change, His heart cannot.

He is a God of unchangeable love. Peace then, tried
believer! Are you passing now through the deep waters?
Who kept you from sinking when wading through the last?
Who brought you through the last fire?
Who supported you under the last cross?
Who delivered you out of the last temptation?
Was it not God, your faithful, unchangeable God?

This God, then, is your God now, and your God forever
and ever! And He will be your guide even unto death!