It was by faith that Abraham offered Isaac as a sacrifice when God was testing him. (Hebrews 11:17)
When trials and tests come into our lives we are tempted to say, Life just isn't fair! This statement should not come as a surprise because to tell you the truth --- Life isn't fair. You aren't going to find fairness while living in a broken world. The sin of disobedience by our forefathers in the Garden of Eden threw the entire world into a state of unfairness and brokenness.
God told Abraham to get packed and move, but he didn't tell him where -- Abraham moved. Then God made promises to him, but didn't tell him when -- he patiently waited. This was followed by an impossible situation of bearing a son at 99 years of age and God didn't tell him how. Finally, after Isaac is born God told Abraham to sacrifice (kill) him and didn't tell him Why. In every situation Abraham obeyed God without question.
As true believers are we willing to follow God's leadership even when we don't know where, when, how, or why?