Because the just shall live by faith, in the Word (of promise) made flesh/realized/fulfilled/”done.”
[Pastor; Heb 2:4]
Case in point: Jesus told His disciples, “All things are delivered unto Me of My Father.”...and, the Apostle Paul concluded: “if (God) spared not His own Son, but delivered Him up for us all, how shall He not WITH HIM also freely GIVE US ALL THINGS?” ...and “All things are yours."
[Matt 11:27; Rom 8:32; 1 Cor 3:21-22]
note. God won't just do “it,” because HE'S DONE “IT” ALREADY; by, and through, faith in His promise(s). “It” is finished! Done! “Before the foundation of the world;” because “All the promises of God are in (Christ) Yea, and in (Christ) Amen/DONE/finished.” [Pastor; John 19:30; 1 Pet 1:18-20; 2 Cor 1:20]
If God said “it,” He will also bring “”it” to pass ...and “do” what He said He will “do.”
[Isa 46:11; Pastor]
As to When will God do “it?” Can you say, “In a moment; in the twinkling of an eye?”
ThenSingsMySoul:
I'M HOLDING FAST TO THE PROMISE
(OF) WHAT GOD HAS SPOKEN TO ME
HE PROMISED ME IF I BELIEVE
I CAN MOVE MOUNTAINS INTO THE SEA
IT'S DONE TODAY, IT'S DONE I SAY
I BELIEVE THAT IT'S ALREADY DONE!