Genesis 15:5-6

Then He brought him outside and said, "look now toward heaven, and count the stars if you are able to number them."  And He said to him, "so shall your descendants be."  And he believed in the Lord, and He accounted it to him for righteousness.

What to do when the promises of God and the circumstances of your life don't match

Trust in the Lord has, I believe, more to do with confidence in the trustworthiness of the Lord and with answers to all questions.  The context of these verses indicate that Abram (this was before his name was changed to Abraham) had a vision of the Lord regarding a child.  He and his wife were beyond the years of childbearing.  They had waited for the fulfillment of a promise to the point that there was no path clear to seeing the promise come to pass.  

The Lord, in this vision, after years of waiting to no avail, repeats His promise and tells Abram not to be afraid, that He is his shield, his very great reward.  Abram, for his part, is full of questions.  "I am an old man, and the heir to my house is Eliezer of Damascus, the son of his servants.  He has no children.  He has questions and concerns.  The Lord is not making any sense and Abram sees no way how this will work out.

The Lord responds by making a statement and saying very little about Abram's questions.  He says that Eliezer will not be the heir (I'm not sure if we every hear about him again) but that Abram and Sarai will have a child, and their descendants will rival the stars in number.  Abram believes the Lord, and it is accounted as righteousness.

The verb for "believe" means "to consider trustworthy".  It's used also in 2 Chronicles 20:20, if you want to look that up.  Abram wasn't afraid to give voice to his concerns and questions, and speak to the Lord about them.  That was not held against him.  Abram, for his part, heard the promise of the Lord again after sharing his concerns, and even though his still did not have answers to his questions, he decided that the Lord is trustworthy, and he was accounted righteous before the Lord.

Followers of Jesus Christ, the Messiah and Son of God, make up those descendants whose number rivals the stars.  (cf. Romans 4:13-25)  There will be times in which the Lord does not seem to make sense, in which the promises of God seem far away with no clear path to them.  Our life settings seem bleak and hopeless.  The question for any one of those "stars" in that moment is not "can I ignore questions or concerns?" or "how can I make this work?" but "do I count my Lord as trustworthy?"  That is faith, and it counts as righteousness before the Lord.