"You are the light of the world. A city that is set on a hill cannot be hidden. Nor do they light a lamp and put it under a basket, but on a lampstand, and it gives light to all who are in the house. - Matthew 5:14–15
If you are a true disciple of Jesus Christ, if you are living the Christian life as it was meant to be lived, then please talk about it. Some Christians who believe that if others observe the way they are living, if others see they are honest and love their family and work hard, then they will notice and will come to Jesus.
While it is true that others will notice, true disciples also need to step it up and tell others about what they believe. As Romans 10:13 says, "How then shall they call on Him in whom they have not believed? And how shall they believe in Him of whom they have not heard? And how shall they hear without a preacher?"
In addition to being salt in the world, Christians are to be light as well. Jesus said, "You are the light of the world . . ." (Matthew 5:14). Someone who is being salt is stimulating in others a thirst for Christ. Someone who is being a light is someone who is proclaiming Christ. So let's be both. There is a place for living it, and there is a place for telling it.
But I would also add that if you are not living it, then please don't talk about it. If you are not going to really try to live as a Christian, then don't go tell others about Jesus, because you actually will do more harm than good.
The world needs to see true disciples of Jesus. What it doesn't need to see are any more bad examples. It doesn't need to see any more watered-down commitments. It doesn't need to see any more bland Christians who are trying to live in two worlds. What we need are living, breathing disciples of the Lord Jesus Christ.