God does not delay in fulfilling His promises

"Working together, then, we appeal to you not to receive the grace of God in vain.
For he says:
“In an acceptable time I heard you,
and on the day of salvation I helped you.”
Behold, now is a very acceptable time; behold, now is the day of salvation."  (2 Corinthians 6: 1 - 2)

There is a time for prayer, a time for waiting and a time for answer.

"I am bringing on that victory, it is not far off,
my salvation shall not tarry;
I will put salvation within Zion,
give to Israel my glory."  (Isaiah 46: 13)

God promises that His answer or salvation shall not be late.  Once the fullness of time arrives, God moves fast.

"The least one shall become a clan,
the smallest, a mighty nation;
I, the LORD, will swiftly accomplish
these things when the time comes."  (Isaiah 60: 22)

"The Lord does not delay his promise, as some regard “delay,” but he is patient with you, not wishing that any should perish but that all should come to repentance." (2 Peter 3: 9)

Why does the Lord appear to be slow in fulfilling His promises?  God is an excellent Father.  Delay in keeping His promises is to allow us maximum time for preparation to receive His gifts.

"Then the LORD answered me and said:
Write down the vision;
Make it plain upon tablets,
so that the one who reads it may run.
For the vision is a witness for the appointed time,
a testimony to the end; it will not disappoint.
If it delays, wait for it,
it will surely come, it will not be late."  (Habakkuk 2: 2 - 3)

Write down the promise of God and date it. Then save it in a place that you can easily retrieve it.  Wait for the fulfillment in prayer.  As you pray for its fulfillment, hope will be born in your heart and "the peace of God that surpasses all understanding will guard your heart and mind in Christ Jesus."  (Philippians 4: 7)

Then one day, you will taste the joy of fulfillment of this promise:
"I have left an open door before you, which no one can close."  (Revelation 3: 8)