Hebrews 12:1 says ‘… let us throw off everything that hinders and the sin that so easily entangles.’
Sickness is not from God. The sickness came through sin. God did not send disease to teach us a lesson; God sent Jesus to teach sickness a lesson. Jesus has given us authority to heal the sick and raise the dead.
1 Pet 2:24 (Amp)
He personally carried our sins in His body on the cross [willingly offering Himself on it, as on an altar of sacrifice], so that we might die to sin [becoming immune from the penalty and power of sin] and live for righteousness; for by His wounds you [who believe] have been healed.