Merriam-Webster’s define the word ‘Filth’ as foul or putrid matter; especially : loathsome dirt or refuse and the word ‘Pure’ as unmixed with any other matter or free from dust, dirt, or taint.

Who can say that they are pure, who life is not foul or putrid, loathsome, dirty or as refuse? Only those who have believed in Jesus Christ and have been washed by His blood as a remission of their sins, by obeying THE TRUTH (Jesus Christ) through the Spirit.  (1 Peter 1:22). No one else is pure. Come now, and let us reason together, saith the LORD: though your sins be as scarlet, they shall be as white as snow (pure); though they be red like crimson, they shall be as wool (Isaiah 1:18) .

The oxymoronic aspect reflected in the infallible Scripture is this. They that are called filthy (when working for Jesus) are indeed the only pure because they are set apart and unmixed with any other matter (the world), sanctified, and free from dirt (stain of sin). So next time someone calls you the filth of the world because of your life in Christ, that only validates that you are blood bought and pure and worthy of being counted with some of the others who were called the same, including Apostle Paul. What a privilege? To be called filthy when serving Jesus is in fact the reflection of the purity of our life as we live for Him.

1 Corinthians 4:13 (KJV)
10 We are fools for Christ’s sake, but ye are wise in Christ; we are weak, but ye are strong; ye are honourable, but we are despised.
11 Even unto this present hour we both hunger, and thirst, and are naked, and are buffeted, and have no certain dwellingplace;
12 And labour, working with our own hands: being reviled, we bless; being persecuted, we suffer it:
13 Being defamed, we intreat: we are made as the filth of the world, and are the offscouring of all things unto this day.

1 Peter 1:22 (KJV)
Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently: