The call to reason arises out of the fact that when God created us He made thinking part of our being. Honest reflection on God's truth leads us to faith and the salvation which is in Jesus Christ.
The order of the day seems to be for nobody to think, but to believe anything. When this is done on a large scale, the strangest notions become incorporated into the common consensus. Then, as we would learn from the old children's story, anyone who would dare suggest the emperor is a naked fool is immediately suspect for daring to be different.
We must decide whether we will simply buy into what is "popular wisdom" or whether we will be careful enough to have our thinking secured by truth and a course of decision making that is not ruled by the tyranny of the mob. This is most important in regard to matters having to do with our soul and its relationship with God. If we are wrong here simply because we find it easier to yield to "group-think" it will not change our individual accountability before God or the eternal consequences.
As our text in Isaiah suggests, God is confident that His plan for salvation from sin will ring true to the honest and reflective mind. There is a sin problem that must be dealt with in a way that justice is upheld. What honest person could really deny that mankind has a problem with self-centredness, abuse of others, and offences toward God?
God's plan to take away that sin is the only one that makes sense. If we are to escape punishment, then someone else must pay the price we cannot. This can only be done by one who is able, willing, and without personal debt. God tells us that this one is His Only Begotten Son, and that the price was paid when He shed His life-blood on the cross. Who else then could rescue us than the resurrected Lord and Saviour? And how else could the benefit accrue to us than as a gift, since by the nature of the problem we have fallen short of our obligations and cannot pay?