In his book Justification and Regeneration Charles Leiter gives a solemn warning against sin:
"One of the most fearful things about sin is its power to harden the one who practices it. The deeper a man goes in sin, the less sin bothers him. According to the Bible, man's very conscience becomes "seared as with a brading iron" (1 Tim 4:2). Every sinner finds himself now committing sins that he once despised, and the sins that he now despises, he will someday find himself committing. It should shock us to remember that Adolph Hitler was once a little boy playing with toys just like the other little boys. Man knows the beginning of sin, but no man has ever known the end of sin. "
Sin is not something to play around with. If ever the Lord brings conviction concerning a sin, that is a wonderful act of kindness and grace on the Lord's part. It should be repented of and forsaken immediately! Sin is dangerous. One who appears to be a true believer today can be an apostate, cursing Christ and loving sin tomorrow... and it all starts with one 'little' sin...
"Take care brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God. But exhort one another every day, as long as it is called "today," that none of you may be hardened by the deceitfuless of sin. For we have come to share in Christ, if indeed we hold our original confidence firm to the end. As it is said, 'Today, if you hear his voice, do not harden your hearts as in the rebellion.' For who were those who heard and yet rebelled? Was it not all those who left Egypt led by Moses? And with whom was he provoked forty years? Was it not with those who sinned, whose bodies fell in the wilderness? And to whom did he swear that they would not enter his rest, but to those who were disobedient?" Hebrews 3:12-18, ESV
The warnings are real. But just as real as the warnings is the glorious salvation in Christ Jesus to all who continue in belief, by God's grace! Hallelujah, we have a SIN-CONQUERING CHAMPION in Christ!
Let us forsake sin and cling to Christ with joyful fear.