God is working whether we see Him work or not. God works based on our believing, not our seeing. Faith is supposed to be a ‘rest’ – knowing that He is doing the behind-the-scenes work. We don’t have to concentrate or strain our attention for Him to work, but rather, He seems to work best (or only works) when we stop looking to ‘make sure’ He is still working. When we are in Faith, our attention can let go of the issue, because ‘by faith’ it is no longer an issue. It has been ‘taken care of in God.’ Yes, we have to continue do our part in obedience, but when we ‘cast our cares’ on Him, we are also casting the focus of that care to Him. It is now His. Can you trust Him in that and rest in it? He wants you to.
Hebrews 4:9 So there remains a Sabbath rest for the people of God. (10) For the one who has entered His rest has himself also rested from his works, as God did from His. (11) Therefore let us be diligent to enter that rest, so that no one will fall, through following the same example of disobedience. (NASB)
There is always going to be an opportunity to have doubts; there is no way around it. Choose to trust Him and His faithfulness. The assurance that we have that He is working is not what we see but what we know about Him and how He is good to His word.