Romans 12:1-2 KJV - I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, [which is] your reasonable service. And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what [is] that good, and acceptable, and perfect, will of God.

It says that your “reasonable service” is to present your body as a living sacrifice.

And it also says if you are transformed by the renewal of your mind, you will then be able to prove what is the will of God.  We “prove” it by doing it. And what is the will of God that we prove once our mind is renewed? 1Thess 5:16-18 tells us the definition of the will of ...