You just need to trust God. How many times has someone told me that? How many times have I said it to myself? And yet, so many times I've failed to understand that properly.
For many years, I think I interpreted "trusting God" as trusting that He would work everything out according to my preference or safety. I'd find myself anxious about an upcoming flight (what if the plane crashes?), a job interview (what if I say the wrong thing? or don't get the job?), confronting a friend, making decisions, dealing with job loss, and much more, and think, "I just need to trust God more." But what that meant to me was trusting that God would keep me safe, protect me, help me ace the interview, help me not to lose a friendship, help me make the right decision, or help me find a job (preferably on my timetable). While God obviously can do all these things -- He is all powerful! -- He doesn't always. He knows the best plan for us, and sometimes He intervenes to protect us from harm but not always. I've learned that trusting God doesn't mean trusting that everything will go smoothly.
The dictionary defines trust as "reliance on the integrity, strength, ability, surety, etc., of a person or thing; confidence" and "confident expectation of something; hope." God is the most worthy object of our trust, completely reliable in every way. However, we must be certain that we are trusting in Him rather than for Him to produce a desired outcome. I can still talk with Him openly in prayer and ask for that outcome. But my faith must not be shaken if I don't get what I want.
The ultimate example, as always, is Jesus. I remember how he prayed in the Garden of Gethsemane and said, "My Father, if it is possible, let this cup pass from Me; yet not as I will, but as You will." (Matthew 26:39) I'm trying to adjust my prayers accordingly.
Recently I was praying specifically that a negative thing would not happen to me. When that thing happened anyway, disappointment filled me. What was the point of praying? Hadn't I shown that I trusted that God could do this for me? Yes, God did have the power to protect me from that situation happening. And I'm certain He had compassion on me as I experienced it. But for some reason, He didn't prevent it. Through it, I learned (again) of the need to apply "Thy will be done" to my prayers just as Jesus taught his disciples to pray. Sometimes I even say something to the effect of "Thy will be done, and help me to accept Thy will." One thing we can always trust is that God will walk through any difficult circumstance with us and will give us the power to endure in our faith if we ask Him.