"Humble yourselves therefore under the mighty hand of God, that he may exalt you in due time: 7Casting all your care upon him; for he careth for you." (1 Peter 5: 6-7)
Most people have the idea that we cast all our cares on God once and for all.
While Jesus did indeed die for us once for all (Hebrews), we are invited to grow in grace and knowledge of Him (2 Peter 3: 18)
We do not receive the fullness of Him to our minds right away.
Instead, we are invited to yield our bodies to him daily as a living sacrifice:
"I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. 2And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God." (Romans 12: 1-2)
This grace into which He invites us in Christ does not come to us all at once, not because God is stingy, but rather because we learn more about the areas of our walk which we still need to submit to His care.
Just as Jesus does not invite us to rest in Him only once, and just as we are invited to keep receiving from Him the gifts of righteousness and grace, so too He invites us to keep casting our cares on Him, because He cares for us.
It is important, therefore, to recognize that we are already blessed with all spiritual blessings in Christ (Ephesians 1: 3), that we are already accepted in the Beloved, in Jesus Christ (Ephesians 1: 6)
Do not think for one moment that any problem you face is too big for God to handle, and never think that anything which you have done will remove His loving protection and salvation from your life.
God Himself has pledged:
"Let your conversation be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee." (Hebrews 13: 5)
"For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come, 39Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord." (Romans 8: 38-39)
You can trust that He cares for you, so keep on casting your cares on Him!