Col 1:9 For this cause we also, since the day we heard it, do not cease to pray for you, and to desire that ye might be filled with the knowledge of his will in all wisdom and spiritual understanding; Col 1:10 That ye might walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God;
This must be the focus of a Christian! If the Christian is thus minded, his/her family life and relationships and love towards the unsaved will eminate light unto those looking on.
I have heard it before said: "There is no better way to be a wtiness for Jesus Christ than to have a lovely relationship with the gospel of Christ Jesus as the center".
Christians are lacking is they are not growing in wisdom and spiritual understanding... it is necessary to walk worthy of the Lord unto all pleasing. And this results in being fruitful in every good work!
Another passage I love-
Ro 6:3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Ro 6:4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
He goes on to say several times that we are free from sin and dead to sin... and in contrast have been made alive in Christ Jesus... given the Holy Ghost, having had the Holy Ghost place the Christian into the body of the Lord Jesus... may we walk in that truth!