Do not be conformed to this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what is the good, pleasing, and perfect will of God.
KJV
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.
ASV
And be not fashioned according to this world: but be ye transformed by the renewing of your mind, that ye may prove what is the good and acceptable and perfect will of God.