“Therefore, I say to you, whatever things you ask when you pray, believe that you receive them, and you will have them. – Mark 11:24

When you ask anything of God, believe, and you shall receive. When you do appeal to His mercy, believe in the mercy. When you are pleading for His help, believe in the help, for there is much power in faith. “According to your faith, be it unto you.”

You all know, surely, what believing is. You say, “I shall go home to pray.” No, no, no; believe, and pray as much as ever you like, and a believing prayer will save you. “Whosoever shall call upon the name of the Lord shall be saved;” but “how then shall they call on Him in whom they have not believed?”

Faith comes first. Believe, then, before you do anything else. May God, of His great mercy, enable, some poor sinner to have done with doings and with feelings, and to trust, just to trust Jesus! There you are, hanging up there in a tree. You are afraid of falling down, so you cling with all of your might. Suppose that a strong man comes underneath, and says, “Here, drop into my arms. I will catch you; I am able to bear your weight.” If you trust, him, you will drop into his arms. That is what you have to do with Christ; trust Him and let go every other confidence. Just drop into His arms, and you shall be saved. Remember, then, that there is no praying aright without believing. ~ C.H. Spurgeon

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