Hypocrites

Yet they seek me daily, and delight to know my ways, as a nation that did righteousness, and forsook not the ordinance of their God: they ask of me the ordinances of justice; they take delight in approaching to God. (Isaiah 58:2)

14 Not giving heed to Jewish fables, and commandments of men, that turn from the truth. 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. 16 They profess that they know God; but in works they deny him, being abominable, and disobedient, and unto every good work reprobate. (Titus 1:14-16)

4 For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, 5 And have tasted the good word of God, and the powers of the world to come, 6 If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame. (Hebrews 6:4-6)

There were a lot of commandments given by the Jewish Rabbis that were additional and often contradictory to the commandments of God in the Bible. Jesus straightened this out in his ministry, but the church needed constant reminding that Jewish laws not found in the Bible were just traditions and were not binding on Christians. Paul is hardly saying that for good people filthy things become pure and for evil people good things like the Bible become filthy.
The pure see the world through God's eyes of love; they avoid (and when appropriate oppose) the filthy, but their thoughts dwell on the pure and the world is a beautiful place. I aspire to this, may I attain it by the power of Jesus in my life.
The defiled fill their minds with evil and often regard pure things as evil. At least in the case of the people Paul is talking about here, they are similar to those in Isaiah 58; they are professed followers of God. They love to talk about the truth and holy living but their character is still defiled as shown by their actions. They speak words of great faith and devotion to God but their behaviour, perhaps including the way they speak shows selfishness and pride.
The last passage included here was referenced in the Treasury of Scripture Knowledge but I don't really see that it is relevant at all. It is a somewhat perplexing verse for myself and many others I think. Those who believe we cannot lose our salvation are perplexed by the reference to losing it. Those who believe  we can lose it are perplexed by the stated impossibility of regaining salvation, which would seemingly condemn us all. All I can say to those two is that it must be referring to the blaspheming away the Holy Spirit which would be surely necessary to do in order to leave the early church with all its amazing miracles and first hand knowledge of Jesus. In our day the church has fallen really quite far and as far as most people know it all we have is a book which is only as powerful as the faith people have in it. Perhaps Paul was speaking more to his own time that all times, but I do not profess to have an answer, only to believe that the Bible is inspired and I will obey everything in it that I am able to understand without ignoring some parts of Scripture to do so.

It is so easy to admire and imitate those who talk big about Jesus and don't live out their profession, I've been guilty of it and just realised recently. It's easy for big talkers to obey the superficial things, often but not always traditions; like manner of eating and dressing. These can be good themselves and show consecration, but the greater matters which show a selfless character must be the overbearing current of the words and actions or the big talker is a hypocrite.
Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone. (Matthew 23:23)
Being conservative in your lifestyle is a good thing, and I believe all consecrated people will move towards being more conservative in their lifestyle. But godly lifestyle without godly character is hypocrisy, Jesus needs to change you from the inside and that will mean big heart-wrenching changes, no matter how good or conservative other people think you are.
So should we ignore conservatives when they are hypocrites or simply not very nice? Not all all, as Jesus taught:
2 Saying, The scribes and the Pharisees sit in Moses' seat: 3 All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: for they say, and do not. (Matthew 23:2-3)
If the Christians were to obey the hypocritical scribes and Pharisees because of their authority, how much more should we obey the authority of God's inspired law when we are rebuked by a modern hypocrite?