Whatever is good and perfect comes down to us from God our Father, who created all the lights in the heavens. He never changes, as a shifting shadow does.
It is very reassuring to know that our loving Father does not change. He is not of one mind one day and an entirely different one the next. The unchangeableness of God's purpose, character, and will are the source of one of our greatest motivations to pray. When you come before Him in prayer referring to His promises, you can be assured that what He will give you is good and perfect.
It is true that the Bible is full of promises. Very few of God's promises in the Bible are absolute in nature. They are, instead, conditional promises, governed by our responses to God, fulfilling certain requirements, and also by the perfect judgment of God. He gives only good and perfect gifts - He will never give one of His children a "blessing" that would ultimately derail His purpose for him or that would be too much for him to handle.
The faithful Abraham and Sarah are good examples of this aspect of God's promises. God promises Abraham, at age 75 that He would make him "a great nation," and "To your descendants I will give this land" implying that he would have children. Yet, He does not give Abraham the promised child when he is 76 or 78 or 80! Finally, the LORD visited Sarah as He had said, and the LORD did for Sarah as He had spoken. For Sarah conceived and bore Abraham a son in his old age, at the set time of which God had spoken to him. Now Abraham was 100 years old when his son Isaac was born to him [Genesis 21:1-2, 5].
Alot had to happen in the lives of Abraham and Sarah - predominantly in terms of spiritual maturity -before God felt the right time had come to give them their promised baby boy. There was one perfect time for this promise to be fulfilled, and God fulfilled it when all the conditions were right.
When you come before Him in prayer referring to the promises He has made, you can be assured that He will answer you and what He will give you is good and perfect. However, God will fulfill His promises when all the conditions are right.
Prayer: My Loving Father, I thank You, for You are reliable and I can trust You knowing You do not change as shifting shadows do. I thank You Father, because You who promised is faithful. As I come before You referring to Your promises over my life, I pray You help me understand the part I have to play in receiving from You. Help me to submit to Your will and Your purpose that I may be able to wait on You for the fulfillment of Your promise, which is alway good and perfect. In Jesus Name, Amen.