Mark 11:23 For assuredly, I say to you, whoever says to this mountain, ‘Be removed and be cast into the sea,’ and does not doubt in his heart, but believes that those things he says will be done, he will have whatever he says.

The spirit of faith is in every believer, you have capacity to believe God for anything. All you need is to open your mouth in God's word and declare. Jesus said this emphatically that, if you say to the mountain without doubt, it will obey you.

Doubt is not a problem once your mouth is engaged. No matter what, if you keep your confession of faith, the situation will respond to your voice. The word of God is quick and sharper than any double edged sword. It has been tried seven times, and, it's also been found to be effective as fire and harmer.

Romans 10:8 But what does it say? “The word is near you, in your mouth and in your heart” (that is, the word of faith which we preach):
9 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved.

Faith is a function of your confession, once you start speaking God's word, faith will arise in your heart. Now, start declaring God's counsel concerning that situation, faith is a natural response to a speaking believer.