To them God has chosen to make known among the Gentiles
the glorious riches of this mystery, which is Christ in you, the
hope of glory.  Colossians 1:27
The Bible goes so far as to say "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."
 Ezekial 3:18
Ezekial 3:20 goes on, "Again, when a righteous man turns from
his righteousness and does evil, and I put a stumbling block
before him, he will die. Since you did not warn him, he will die
for his sin. The righteous things he did will not be remembered,
and I will hold you accountable for his blood."
Read what the Apostle Paul said about his pastoral work in Acts
20:25-31:  
"Now I know that none of you among whom I have
gone about preaching the kingdom will ever see me again.
Therefore, I declare to you today that I am innocent of the
blood of all men. For I have not hesitated to proclaim to you
the whole will of God. Keep watch over yourselves and all
the flock of which the Holy Spirit has made you overseers.
Be shepherds of the church of God, which he bought with his
own blood. I know that after I leave, savage wolves will come
in among you and will not spare the flock. Even from your
own number men will arise and distort the truth in order to
draw away disciples after them. So be on your guard!
Remember that for three years I never stopped warning each
of you night and day with tears."
Spreading the Gospel is not a suggestion, it is Jesus' command to His
disciples.  Mark 16:15 says:  He said to them,
"Go into all the world
and preach the good news to all creation."  
 
But rather than going about, pointing fingers at sin in our society,
(
"..for all have sinned and fall short of the glory of God"
Romans 3:23.
) we would prefer to simply spread the Good News
of the Gospel!  1 Peter 3:15-16 says
"In your hearts set apart
Christ as Lord. Always be prepared to give an answer to
everyone who asks you to give the reason for the hope that
you have. But do this with gentleness and respect, keeping a
clear conscience, so that those who speak maliciously
against your good behavior in Christ may be ashamed of
their slander."
For, in order to change our society, we must first let the Spirit of the
Lord change men's hearts.  The first thing we must do, is tell them!
"So if anyone is in Christ, there is a new creation: everything
old has passed away; see, everything has become new!"
2
Corinthians 5:17