Ezekiel 3:18-19 (NIV)
When I say to a wicked man, 'You will surely die,' and you do not warn him or speak out to dissuade him from his evil ways in order to save his life, that wicked man will die for his sin, and I will hold you accountable for his blood. But if you do warn the wicked man and he does not turn from his wickedness or from his evil ways, he will die for his sin; but you will have saved yourself.
When God saves someone, He gives them eternal life. We teach that it is impossible to lose this eternal life once God has granted it. What's the point then of hanging around here if Heaven is going to be so much better? God has left us here for a purpose, to warn others of His wrath against sin, and to tell them the good news of Christ. Ezekiel had this dire and solemn responsibility to warn people with the words of God. In fact, he was held accountable for that warning--not for the effectiveness of it, but just for giving it. So too, I am responsible for telling others of the good news of salvation in Jesus Christ. If I fail to do so, I'll have to give an account before God.
So why am I not responsible for the e.ffectiveness of the message? Because the power is not in me but in the message which is the word of God.
Hebrews 4:12 (NIV)
For the word of God is living and active. Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart.