Heb.11:1"Now FAITH IS THE SUBSTANCE of things hoped for,the evidence of things not seen."
Many times in excercing faith,many are so concerned about how the miracle will happen.They want to know the process by which it will occur,they seek a sign.
Seeking God's direction as to which way to go is good,but don't put your faith in the process,put your faith in the substance.
Eg.When ISREAL came to the crossing point of the Red Sea at the gulf of Aqaba,they must have wondered by what process or means,they were going to cross over.
If their faith was in the process,it would have failed.
Their faith had to be in God's word.
Abraham's mind may have raced through the process of how God was going to bring Isaac into being,but he chose not to bother about how,he focused his attention on the substance -the evidence and reality of an unseen Isaac.
What was important was his vision of an unseen evidence,not how God was going to do it. Selah!