The equation is simple. If God requires perfect righteousness and perfect holiness to survive His perfect judgment, then we are left with a serious problem. Either we rest our hope in our own righteousness, which is altogether inadequate, or we flee to another’s righteousness, an alien righteousness, a righteousness not our own inherently. The only place such righteousness can be found is in Christ – that is the good news of the Gospel.
R.C. Sproul