Romans 8:5 Those who live according to the flesh have their minds set on what the flesh desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires.
Where is your heart set at? Where is your mind set at? Are you constantly worrying about earthly matters?
It may be easy for a Christian to say “think of spiritual things” but when you are drowning in earthly matters, all you can focus on are those things.
God wants you to stop thinking you have to do it all and give more to Him to manage and to release you from.