The obedience of faith
Upon God's addressing us by His Word, inscripturated in the Holy Scriptures, we are meant to obey. Obedience, that is pleasing obedience, springs from faith. Faith is the unseen root; obedience is the seen fruit.
Such obedience, as evidenced by Abraham and all the faithful, must be total and unreserved; continuing and unwavering (Hebrews 11:8; 10:38,39).
It implies separation: a radical separation from the days when we were yet without Christ and without hope; it might also imply a practical separation, as it meant to Abraham (Genesis 12:1; Isaiah 51:2). This may spell lonliness, especially for men called for the gospel ministry. Believers are meant to lay aside every encumbrance and not to be entangled in secular affairs, for though we live in the world we do not form a part of it. Ours is the pilgrim way; we must brook no interference from any other source of authority. The pilgrim leaves everything behind, and travels light. With his eyes set upon the Lamb, we are to follow, allowing no distraction.
The obedience of faith means also an absolute trust in God, though we may lack adequate information, yet what God tells us is enough for the time being. Abraham started to travel towards the land God would show him, but curiously enough, he did not know which land was it at the time he set out (Genesis 12:1). God gives enough light; as we progress along the way, he grants more light.
To obey God in a world set against Him demands courage and integrity of heart. It can, to be sure, lead to an unsettled life, as Abraham experienced. It must have been different for him living in tents rather than in a solid house in Ur.
The obedience of faith impels us to move from place to place, worshipping our God whom we don't see and yet whom we're convinced is the Absolute Reality.
A Christian today may become convinced that God is calling him to the mission field, though he feels inadequate and untrained. He must be prepared for the worst, for the worst, if it is God's will for him, is the best. To obey in faith means maintaining the purity of the gospel even at the cost of experiencing resisting from church members and a feeling of lonliness.