For what the law was powerless to do in that it was weakened by the flesh, God did by sending His own Son in the likeness of sinful man, as an offering for sin. He thus condemned sin in the flesh, — Romans 8:3

Here's the heart of the Gospel: the law couldn't save anyone — it was weakened by the flesh, powerless to make us right — so God did what the law couldn't do. He sent His own Son in the likeness of sinful flesh and condemned sin in the flesh. The law had only a shadow of the good things to come, never able to perfect the worshiper. But through Christ, everyone who believes is justified from everything the law couldn't acquit you from. He partook of flesh and blood so that through death He might destroy the one who had the power of death.