How then shall they call on Him in whom they have not believed? – Romans 10:14

Since we must pray, and only by prayer can find salvation—and there is no praying without believing—may the Lord help us to believe, for how shall we pray aright unless we do believe?

I think that I have persons here who have commenced to pray, who have begun pleading with God. I hope, dear friends, nay, I feel sure of it, that, if that prayer is sincere, there is a measure of faith in it, for would you ask God to save you if you did not believe that you needed to be saved? There is a measure of faith in that. Would you ask God to save you if you did not think that there is a way of salvation by which He can save you? There is a measure of faith in believing that.

I think that you believe that there is a Savior. There is a measure of faith in that; and, I hope, a measure of saving faith, too, in your believing that, notwithstanding all your sins and sinfulness, there is a Savior provided, who is able to save to the uttermost them that come unto God by Him. You may not have much faith; but you must have some faith if you are really praying to God from your heart and entreating Him to save you.

I think, too, that you must have a little faith that the Savior will save you. You have been praying to Him to do it. Would you have expressed that desire, and have come to Him in prayer about it, unless there was some kind of sediment of faith in your heart? I want to put it very gently to you, yet very plainly. Remember, faith is not measured by the quantity, but by the quality. A man of strong faith is happier, but he is not more truly saved, than a man of weak faith, so long as he has any faith at all. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2327.cfm