What does it mean to give your body as a living sacrifice? How is this manifest?
Romans 12:1. I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service.
It means, as the latter part of Romans 12:1 indicates, to live a life that is separate from the world around you and acceptable to God. It means not being conformed to the world around you by acting like the world acts, but rather being changed by having your very way of thinking about things renewed to accord with the good and acceptable and perfect will of God. It means living a lifestyle that accords more and more with the lifestyle set forth in Ephesians 4-6, which is the worthy walk (lifestyle) of the believer, in keeping the unity of the Spirit, in putting off the old man (manner of life) and putting on the new man, in walking in love, in walking in light, in walking circumspectly, in submitting to other believers in the fear of God, in putting on the whole armor of God, and in praying.