Why do I help thee?

In Isaiah 43:2 the Savior is talking to Israel and says:

"2.When thou passest through the waters, I will be with thee; and through the rivers, they shall not overflow thee: when thou walkest through the fire, thou shalt not be burned; neither shall the flame kindle upon thee."

Now why would the Lord go through all our trials with us? He says in verse 4:

"4. Since thou wast precious in my sight, thou hast been honourable, and I have loved thee: therefore will I give men for thee and people for thy life."

And just to solidify how dedicated he is to us he continues:

"5. Fear not: for I am with thee."

C.S. Lewis had an insight to add on to why we as mortals and prone to so much failing are precious in his sight.

"There are no ordinary people. You have never talked to a mere mortal. It is a serious thing to live in a society of possible gods and goddesses, to remember that the dullest and most uninteresting person you talk to may one day be a creature which, if you saw it now, you would be strongly tempted to worship."

C. S. Lewis (The Weight of Glory)