It is a statement John Owen is famous for:
Be killing sin, or it will be killing you.
However, it was his King who vividly spoke of the deadly nature of sin long before him.
42 “Whoever causes one of these little ones who believe in me to sin, it would be better for him if a great millstone were hung around his neck and he were thrown into the sea.
43 And if your hand causes you to sin, cut it off. It is better for you to enter life crippled than with two hands to go to hell, to the unquenchable fire. 45 And if your foot causes you to sin, cut it off. It is better for you to enter life lame than with two feet to be thrown into hell. 47 And if your eye causes you to sin, tear it out. It is better for you to enter the kingdom of God with one eye than with two eyes to be thrown into hell, 48 ‘where their worm does not die and the fire is not quenched.’
49 For everyone will be salted with fire. 50 Salt is good, but if the salt has lost its saltiness, how will you make it salty again? Have salt in yourselves, and be at peace with one another.”
(Mark 9:42-49, English Standard Version)
Such language from my King fires me up to take sin seriously, this seriously. For if I don't, my saltiness in a bland world filled with evil will be lost.
And that would kill me.