Can soap get dirty? Soap doesn’t really get dirty, but if left in the dirt it does lose its potency.
Christians can treat sin the same way. The blood of Jesus cleans away the dirty stain of sin, but if we remain steeped in sin we lose our potency.
Why does potency matter?
If I have no potency, I cannot affect the world around me the way God wants me to. I have no spiritual-power, I have to rely on my own power, apart from God. I have no spiritual-authority. My relationship with God will seem distant, dry, absent. My heart will be crusty, unable to love and value others. I will miss God opportunities–or when one hits me on the face, I won’t have the wisdom to know what to do… I could write for days. I won’t. You get the picture.