This is probably a question you seldom consider. And at first bounce the answer you might be tempted to give is cancer.
But let’s think this through. Cancer can take nothing from you that will damage your relationship with God and with those close to you. Sin can do this and much more. Cancer cannot keep you from God, but sin certainly can.
Cancer is something most people take seriously. Sin – not so much. Spending time and money to find the right treatment schedule is done without question. You ask people to pray for you and your condition. You give money to cancer research. You might even put more money in the offering plate!
Upon receiving a cancer diagnosis schedules are redone and life-style changes are made overnight. Specialists are consulted. Appointments with the doctor are made to fit the doctor’s schedule not yours.
But what about a diagnosis of anger towards your spouse or children? Your focus is typically upon the people that anger you rather than on curing your sin of anger. The idea of asking the pastor or seeking a biblical counselor to help you change is kind of an afterthought. You would not alter your work schedule or give up the things you like doing to address this sin. It is just anger and really, you would not be angry if others did not make you angry.
You get the point.
Sin or cancer, what do you fear most?