In 1 Timothy 4:1-3, Paul said:
Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils; speaking lies in hypocrisy; having their conscience seared with a hot iron; forbidding to marry, and commanding to abstain from meats, which God hath created to be received with thanksgiving of them which believe and know the truth.
Here Paul provides a warning to counter false teachers. Paul is telling the original audience (his readers) that false leaders teach that purity is attained (and maintained) by adherence to rules and the external observance of ceremonies. Paul was no fool, and he knew that ceremonies laid line upon line upon line is a stack of nonsense. Rubbish, that.
Mere adherence to rules and external observance of ceremonies, when attempted in order to secure personal purity, is absolute nonsense. It’s simple really: man’s problem is located in the heart, hence, the problem can only be resolved with a solution that is also located in heart (and addresses and fixes the heart). King David understood this. In Psalm 51 he said:
Wash me thoroughly from my iniquity, and cleanse me from my sin….Behold, I was shapen in iniquity; and in sin did my mother conceive me. Behold, thou desirest truth in the inward parts: and in the hidden part thou shalt make me to know wisdom. Purge me with hyssop [which was used to sprinkle the doors of the Israelites in Egypt (Ex. 12) and for purification and sacrifices (Lev. 14; Nu. 19)], and I shall be clean: wash me, and I shall be whiter than snow….Create in me a clean heart, O God; and renew a right spirit within me.
Create in me a clean heart! That is the heart-cry of every Christian, those who have the unction and knowledge provided by the Holy Spirit (1 John 2:20). Christians call out to God, “Create in me a clean heart!”– and it is only the Holy Spirit who enables and empowers them to do so, because in Christ they’ve been adopted by God. Christians call out to God because they know that only God, who is the One that looks at the heart, can change the heart — Christians know this because God did it, to them!
The heart is the foundation of our will, the heart is back of every human desire, and the disposition of the heart is determined by one’s nature. Therefore, human will and desire is the overflow (flows from) the heart which is controlled by one’s nature. What are the implications of this? For starters, if we are still in our sin/our fallen nature (if we are still in the first Adam), then we can’t even ask God to cleanse us, or give us a new heart, or renew our spirit, etc. We can’t ask for those things because we don’t have the appetite for them; we lack desire for purity. However, if we have a new nature (i.e., if we are justified, if we are in the second Adam, Jesus Christ), then we can cry out, by the empowerment of the Holy Spirit, and ask God to sanctify us — ask God to cleanse us, to renew, that is, to make pure.
Remember what Paul said above — if someone is teaching purity is attained by or the result of adherence to rules and maintaining ceremonies, instead of being a result of God changing our heart and renewing our spirit, then they are a false teacher and they are “speaking lies in hypocrisy.” Therefore, avoid the lies, run away from any attempt of works righteousness/purity, and run to God, the one who knows the heart and can change the heart! The purity of man is and can only be a work of God.