The answer to this is simple: We must dedicate time to studying the word of God to know him and discover who he is and how he acts toward us, his children.
21 Jesus answered and said to them, Truly I say to you, if you have faith and do not doubt, you will not only do this to the fig tree, but if you say to this mountain, Be taken up and cast into the sea, it will be done.
Matthew 21:21
If through the word of God we believe who God is, we understand with certainty what he will do and how he will do it, everything that he has promised, even when our faith fluctuates for any reason we will return to the fountain. There are times when we also doubt or hesitate in our prayers, there are times when we have unbreakable faith and other times when we present ourselves before God with a minimal hope that he will hear us and much more that he will respond to us.
We tend to be unaware that in any situation God is acting in our favor, we fail to discern God's actions at all times and in different circumstances, we turn to God in prayer and it seems that "Nothing happens." But this is according to our reality at that moment, perhaps we are not impregnated with the hope that the word of God offers us, we must understand that God is ALWAYS acting and only for our good, he has a correct moment for each response, whether in foreground or background is always acting.
Not knowing concretely the ways of God can lead us to not being able to wait with faith, we become disappointed, and our gaze strays from the objective. Our prayers are accompanied by the expectations we have according to what God can do and we feed all this with His word, which is why we anticipate acting according to the knowledge we have. If our knowledge of God is poor, they will be poor. our expectations.
Knowing God and what he will do in our lives totally changes the panorama of our future, it does not give stability in faith while we are waiting on him.
For the doubts that arise daily to be suppressed, we simply must read the Bible to understand how God works and what he will do in our lives.