The litmus test of a believer
measure fear and you will find if you are lying
So you think you are a believer and have faith in an entity that controls everything and anything that happens under its watch is governed by its unlimited wisdom and knowledge.
If you are true in your claim that nothing should worry you, nobody who can try to harm you will not be able to if the will of God is not involved.
It goes like that anything that happens to you is for your benefit since if God loves you ( and it does) then trials and hardship one bears are not punishment but acts of God so people can learn and become strong and know if they truly believe in God.
Humans are weak creatures and any fear of loss and danger makes them stop in their tracks, they tremble, stop reasoning become self-centered, and lose empathy and kindness.
It's the feeling of fear that drives most of our actions, fear of losing someone, missing an opportunity, losing status and place in society, and not getting respect or a position one desires.
But ..
If faith and reliance on an entity remove that feeling; consider how free an individual will become and how much self-sufficient.
Even if the whole world stands in opposition to its idea, his way of life. This feeling of being in danger will not affect the attitude toward life or subjugate it to follow what is popular and approved by society.
Indeed, those who have said, “Our Lord is Allah,” and then remained on the right course — there will be no fear concerning them, nor will they grieve. 46:13
Those who believe, and do deeds of righteousness, and establish regular prayers and regular charity, will have their reward with their Lord: on them shall be no fear, nor shall they grieve. 2:277
There is no activity you may be engaged in ˹O Prophet˺ or portion of the Quran you may be reciting, nor any deed you ˹all˺ may be doing except that We are a Witness over you while doing it. Not ˹even˺ an atom’s weight is hidden from your Lord on earth or in heaven; nor anything smaller or larger than that, but is ˹written˺ in a perfect Record. There will certainly be no fear for the close servants of Allah, nor will they grieve. 10:61–62
Even the idea of hell and heaven would not affect an individual to stop in its acts or its ideals are not derived by being put in a certain condition eternally because its love and reliance on God is far greater than the fear of losing out to it.
Next time if you encounter anyone claiming to be a believer; then you know how to test the claim one is making.