A man will sometimes say to himself – indeed we have heard it openly suggested – that as David was forgiven his sin, and it is evident that God makes much allowance for human weakness, surely we in these days shall be excused for doing such and such things.
These fleshly reasoners fail to perceive that by the very fact of their indulging such reflections they move the transgression of fleshly weakness into the category of deliberate despising of God’s law. If David, previous to his transgression had deliberately reasoned the matter out and concluded that since God had shown mercy in other cases, it might be worth while to undertake the risk of sinning, we should never have heard of him as an example of rectitude. In all probability he would have been treated with the severity shown to other despisers and wilful transgressors of the law.
Islip Collyer, Conviction and Conduct, page 79.