BURNING OF SKIN - 4:56

LITERAL TRANSLATION 

4:56 - Indeed (إِنَّ) those who (الَّذِينَ) are ignorant (كَفَرُوا) with our signs (بِآيَاتِنَا), soon (سَوْفَ) We will burn them (نُصْلِيهِمْ) in rage / fire (نَارًا) - Every time (كُلَّمَا) to make them perfect / mature / ready to do their job (نَضِجَتْ) by experiencing suffering / flogging / hurting them (جُلُودُهُمْ). We will change their (بَدَّلْنَاهُمْ) hurt / suffering (جُلُودًا) other than it (غَيْرَهَا) - [here pronoun 'it' is feminine that points to the maturity / evolving process will not be the same again], so they may taste  (لِيَذُوقُوا) the sweet illusionary life (الْعَذَابَ). Indeed your Conscience / Consciousness (اللَّهَ) is ever (كَانَ) Strong (عَزِيزًا) and Wise (حَكِيمًا).

CONTEXTUAL INTERPRETATION

4:56 - Indeed those who are ignorant with our signs, soon life will burn them in fire of rage this is done to make them perfect / mature / ready to do their job every time / they have to suffer burn their skins / get hurt, facing the turmoil of life, time and again, they will pass through the process of attaining perfection, in this process their suffering will not remain the same, their journey of life will be different than the present life so they taste the sweet illusionary life. Indeed your Teacher (Life / Allah) is Strong and Wise.