My son, do not walk in the way with them, Keep your foot from their path; So are the ways of everyone who is greedy for gain; It takes away the life of its owners. (Proverbs 1:15, 19 NKJV)
There are many paths in life that lead to death, however many of them are subtle, and not all of them lead to physical death. Spiritual death can often be the result of wandering from God's way.
Proverbs tells is to keep our feet from the wicked's path; to completely avoid it, not even setting foot upon it. Why should this verse be so emphatic in warning us not to cross paths with the wicked, even by accident?
If we indulge in something unGodly even once, the images and the experience never leaves our minds. It becomes a constant source of temptation and creates a conflict and struggle in our spirit.
It only takes a toddler one taste of something sugary for them to be unsatisfied with the food that is good for them. So one taste of wickedness can make us unsatisfied with God, driving a nail into the coffin of our walk with Him.
These are some of the reasons we are so strongly warned to flee all appearances of evil. What the eye doesn't see, the heart doesn't grieve. Therefore if we forsake the wicked path, the tempting things of the world will have nil effect on us because if we never indulge in them, we can't be tempted by them.
Let us then follow the wisdom of Paul to Timothy: "Flee also youthful lusts; but pursue righteousness, faith, love, peace with those who call on the Lord out of a pure heart." (2 Timothy 2:22 NKJV)