An interesting fact is that you will hardly win a victory or a breakthrough as long as some problem is the biggest and most important thing in your life. What I mean is that sometimes we think about our difficulties and challenges so much that they grow like mountains and block the view of everything else. They become the "biggest thing" in our lives, and our whole thinking revolves only around them.

Jesus says that we cannot serve two masters and that we should not worry. What he's really saying is: don't dwell on it, don't serve your worries, don't serve the problem. He's concerned about the right perspective.

We are meant to think differently — to renew our minds, as the Bible puts it — and to concentrate on the promises of God, to think about them, to occupy ourselves with them.

If we want to be freed from problems, we have to stop serving them. We must not allow them to dominate our thought life.

For our problems are not the biggest thing in our lives.
Our God is!

No one can serve two masters; for either he will hate the one and love the other, or else he will be loyal to the one and despise the other. You cannot serve God and mammon.
Therefore I tell you, do not be anxious about your life, what you will eat or what you will drink, nor about your body, what you will put on. Is not life more than food, and the body more than clothing?
Matthew 6:24-25

For though we walk in the flesh, we do not war according to the flesh. For the weapons of our warfare are not of the flesh but have divine power to destroy strongholds. We destroy arguments
and every lofty opinion raised against the knowledge of God, and bringing every thought into captivity to the obedience of Christ
2 Corinthians 10:3-5