The Power of Salvation Titus 2:11-15

Titus 2:11-15 Knowing God’s saving involvement in this world strengthens our conviction to live in light of His holy purposes.

Corresponding Article

Titus 1:15 on All Things Are Pure

But my difficulty is how can “all things” in Titus 1:15 become pure, holy, wholesome to the faithful Christian. Whilst there is another counterpart scripture in 1 Thessalonians 5:21 which instructs us to “prove all things and hold fast what is good and pure”?