I feel an empty cross / cross with Christ is essential in a Christian worship place inside or outside - not for Christians but for non-Christians, especially in a place where majority are non-Christians. It is the cross that comes to a person's mind when he thinks of Christianity. One day or the other the Spirit of God will prompt him to know the story behind it.
At the Cross, At the Cross, where I first saw the light
And the burden of my heart rolled away,
It was there by faith, i received my sight,
And now i am happy all the day.
For Christians it is a reminder, for non-Christians it is a pointer to salvation. We need the cross (with or without Jesus on it). I feel the church has reformed well out of idol worship and all of us know it.
When we do not have cross at all anywhere in sight, God will still do His work. He may have to rely on the Christians' living as testimony....