'This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us. And if we know that He hears us in whatever we ask, we know that we HAVE the requests which we have asked from Him.' [1 John 5:14,15]
We know from Hebrews 4:3 that God's works were finished from the foundation of the world. Psalm 119:89 says His Word is settled forever, and 2 Corinthians 1:20 says that as many as are the promises of God, in Him [Jesus] they are YES.
We see that, in the natural line of time, people of the Old Covenant looked forward to the completed work in Jesus...we look back to the completed work in Him. But really, it was all completed from the foundation of the world.
Mark 11:24 says "Therefore I say to you, ALL THINGS for which you pray and ask, BELIEVE THAT YOU HAVE RECEIVED THEM, and they will be granted you."
Jesus said "If you ask Me ANYTHING in My name, I will do it" and "If you ask the Father for ANYTHING in My Name, He will give it to you." [John 14:14; John 16:2]
Consider these:
Stop trying to figure out the 'how' and believe God. Everything belongs to you now...NOW faith IS the assurance [Gr. hupostasis...substructure, foundation, that which is firm, having actual existence, substance, real being...the substantial quality of a thing] of THINGS HOPED FOR, the conviction [Gr. elegchos...a proof, that by which a thing is proved or tested] of THINGS NOT SEEN. [Hebrews 11:1]
That's why God tells us to '...look NOT at the things which are seen, but at the things which are NOT SEEN; for the things which are seen are temporal [Gr. proskairos...temporary, passing, for a season], but the things which are not seen are eternal.' [2 Corinthians 4:18]
'By faith Noah, being warned by God about things not YET seen, in reverence prepared an ark for the salvation of his household...' [Hebrews 11:7]
"So will My word be which goes forth from My mouth; It will not return to Me empty, without ACCOMPLISHING what I desire, and without SUCCEEDING in the matter for which I sent it." [Isaiah 55:11]"I am watching over My Word to perform it." [Jeremiah 1:12]