It would be good if you would lose a few pounds. It would be a good idea to exercise more. You should really spend more time talking with your wife and kids. What you really ought to do is slow down and stick to a plan.
These are all bits of advice aimed at no one in particular. Each may be advisable in a given situation - perhaps profitable. But what we will find throughout human history, and in our own individual experience, is that profitability ≠ probability. The fact that if would be good, or that you should, or ought - it doesn’t really matter, because just as profitability ≠ probability, so also should ≠ want. We do what we want.
It is hard to argue with the profitability of the Gospel. Accept this diagnosis (that we are all sinners) and receive this cure (believe and follow Jesus as the only hope for salvation) - and you will be saved. But do the majority of those who hear the Gospel accept and receive? No. Profitability ≠ probability. If a person at enmity with God really cannot save himself, and if Jesus really is the central figure in all of human history, then yes, you really should accept and receive him. But the matter stands and falls on his question: do you want to? Why that question? Because should ≠ want.
The prophet Isaiah says the reason for our reluctance is not in the offer, nor in the presentation. The reason is in our own persons. We are “a rebellious people, walking in a way that is not good, following (our) own thoughts.” Rebellious. Stubborn. Self-directing and wise-in-our-own-eyes. That’s us. And that is why we often do the dumbest things, like ignoring good advice, and clinging to the unprofitable path.
What might happen if we, just for this season, gave in and did things God’s way? Pick an area of life. Maybe it has to do with your thoughts, or words, or a relationship, or what you listen to - what if you just did the improbable? Maybe you would find it to be actually profitable.