Matthew 21:21 And Jesus answered and said to them, “Truly I say to you, if you have faith and do not doubt, you will not only do what was done to the fig tree, but even if you say to this mountain, ‘Be taken up and cast into the sea,’ it will happen.
Because the world is fallen and every human being is fallen in nature, we naturally doubt God. Even Mary, who Roman Catholics built up into basically a goddess doubted God as Gabriel said “The Lord is with you”, and she could not grasp at what that meant because she naturally doubted herself in His eyes.
The Apostle Peter showed his doubt as he walked on the water towards Jesus and began to sink because doubt crept in. Again, it is natural for us to doubt, it is unnatural to not to doubt in God but to trust in Him completely.
Try this the next time you are for example with friends or family in a traumatic or dramatic situation and say “let us trust in God alone!”. Then exhort them to trust in His sovereign will. You will most likely see doubt by scoffing and mocking by many in that group even by the most ardent professing Christians.
Doubt is something we grow out of by the power of the Holy Spirit. If you are staying in the word and are actually born-again, you should find yourself growing into trust each day in God alone. Doubt should be leaving. So with this, don’t expect a newborn believer to not to doubt in God, that doubt will start to leave, but it isn’t an overnight change from doubt to full trust as we are still in the flesh. The evidence of a newly born again new creation however is the START of the removal of doubt in God of which this process is growing. So if you have been saved for awhile, your trust in God should be much greater than any newborn but don’t boast in this, rather boast ONLY in Jesus Christ who made this possible.
Say to yourself “I trust in God alone” until you actually believe each word which just came out of your mouth. It might take years for some, but with the power of the Holy Spirit your doubt should be leaving you. As you trust more and more in the Almighty God, your peace and rest is also growing to an eternal joyful state. Trust in Him alone!