The cross enforces three truths – about ourselves, about God, and about Jesus Christ.

First, our sin must be extremely horrible. Nothing reveals the gravity of sin like the cross. For ultimately what sent Christ there was neither the greed of Judas, nor the envy o f the priests, nor the vacillating cowardice of Pilate, but our own greed, envy, cowardice and other sins, and Christ’s resolve in love and mercy to bear their judgment and so put them away. It is impossible for us to face Christ’s cross with integrity and not to feel ashamed of ourselves. Apathy, selfishness and complacency blossom everywhere in the world except at the cross. There these noxious weeds shrivel and die. They are seen for the tatty, poisonous things they are. For if there was no way by which the righteous God could righteously forgive our unrighteousness, except that he should bear it himself in Christ, it must be serious indeed. It is only when we see this that, striped of our self-righteousness and self-satisfaction, we are ready to put our trust in Jesus Christ as the Savior we urgently need.

Secondly, God’s love must be wonderful beyond comprehension. God could quite justly have abandoned us to our fate. He could have left us alone to reap the fruit of our wrongdoing and to perish in our sins. It is what we deserved. But he did not. Because he loved us, he came after us in Christ. He pursued us even to the desolate anguish of the cross, where he bore our sin, guilt, judgment and death. It takes a hard and stony heart to remain unmoved by love like that. It is more than love. Its proper name is ‘grace’, which is love to the undeserving.

Thirdly, Christ’s salvation must be a free gift. He ‘purchased’ it for us at the high price of his own life-blood. So what is there left for us to pay? Nothing! Since he claimed that all was now ‘finished’. There is nothing for us to contribute. Not of course that we now have a license to sin and can always count on God’s forgiveness. On the contrary, the same cross of Christ, which is the ground of a free salvation, is also the most powerful incentive to a holy life.. But this new life follows. First, we have to humble ourselves at the foot of the cross, confess that we have sinned and deserve nothing at his hand but judgment, thank him that he loved us and died for us, and receive from him full and free forgiveness. Against this self-humbling our ingrained pride rebels. We resent the idea that we cannot earn – or even contribute to – our own salvation. So we stumble, as Paul put it, over the stumbling block of the cross.

(THE CROSS OF CHRIST, John Stott, p.83f.)