NET
15 All is pure to those who are pure. But to those who are corrupt and unbelieving, nothing is pure, but both their minds and consciences are corrupted.
Darby
15 All things [are] pure to the pure; but to the defiled and unbelieving nothing [is] pure; but both their mind and their conscience are defiled.
KJV
15 Unto the pure all things [are] pure: but unto them that are defiled and unbelieving [is] nothing pure; but even their mind and conscience is defiled.