But not everyone possesses this knowledge. Some people are still so accustomed to idols that when they eat sacrificial food they think of it as having been sacrificed to a god, and since their conscience is weak, it is defiled. (NIV)
Nevertheless, not all [believers] possess this knowledge. But some, through being all their lives until now accustomed to [thinking of] idols [as real and living], still consider the food [offered to an idol] as that sacrificed to an [actual] god; and their weak consciences become defiled and injured if they eat [it]. (AMP)
Howbeit there is not in every man that knowledge: for some with conscience of the idol unto this hour eat it as a thing offered unto an idol; and their conscience being weak is defiled. (KJV)