Read Romans 6:12-23.
Therefore, do not let sin exercise dominion in your mortal bodies, to make you obey their passions. (Romans 6:12)
After saying in chapter five that salvation is a free gift of grace through faith, Paul warns us in the first half of chapter six not to take sin lightly as a result. “Shall we sin the more that grace may abound? By no means.” “Consider yourselves dead to sin.”
Assuming we do not take sin lightly but wish to overcome it, how do we go about it? Where do we start?
Paul starts with the passions of sin. A passion is any powerful emotion or appetite, such as love, joy, hatred, anger, greed, envy, or hunger. In a sense, passions happen /to/ us. We suffer passions. We are passive. Thus, Christ’s suffering is called his /passion/.
The body of sin in us has passions, for example, greed. When we are hungry, desiring food is normal and rightly ordered. Desiring more than we need, at the expense of others, is greed. It is a disordered or sinful passion. There is no sin in having the passion—it happens /to/ us (although it may indicate a disordered state). Paul says that it is our part not to let such passions have dominion—not to /obey/ them.
Think of holiness not as being free of sinful desires but as fighting them. Maybe, someday, as not even noticing them. They no longer have power over you, to make you obey them. You are dead to them.
Ultimately, passions flow out of what you love. Do you love security, respect, ease, comfort, power, pleasure, willfulness, all for yourself? Or, have you heard the promise, do you have faith in him who made it, do you seek it now above all? In that case you are free from the dominion of sin, no longer bound to those passions, able to disobey them and pursue the great treasure. Go for it.
The sin isn’t in having passions and desires, or in pursuing them. The sin is in pursuing /disordered/ passions, selfish desires. The whole law is summed in this: love God above all and your neighbor as yourself.