James 5:7 Be patient therefore, brethren, unto the coming of the Lord. Behold, the husbandman waiteth for the precious fruit of the earth, and hath long patience for it, until he receive the early and latter rain.

Patience is a virtue that every child of God must cultivated. The promises of God for you  require your patience, don't rush things. God is not slow, you are the one measuring things based on your human calendar. He that will come will come, the just must be living by faith. 

Hebrews 10:36 For ye have need of patience, that, after ye have done the will of God, ye might receive the promise. 37 For yet a little while, and he that shall come will come, and will not tarry. 38Now the just shall live by faith: but if any man draw back, my soul shall have no pleasure in him.

Did you read that? He that will come is going to come through for you. You need patience after you have done the will of God. Patience reflection of our deep trust in God and that His plan and timing are perfect, even when we don't understand them fully yet. Trust in the Lord with your heart. 

Abraham and Sarah received God's promise, yet the opposite was the situation for them at the initial stage. They patiently waited for His promise to have a child and become the father of many nations, even when it seemed impossible. Don't cast away your confidence in God, keep His promise always in your heart and your mouth.