This point I think is hard for us to understand. We look at ourselves as impure and incapable, which is a continuous state. But the Lord implies the priests could wash and cleanse themselves and enter the temple Holy. Jesus emphasised this by talking about what made people impure, and that our hearts needed to be purified and cleansed.
Emotionally we project ourselves as static people who identify a particular way, except the Lord is addressing us as His Holy pure people. For this to be true we must have got something wrong, to continually condemn ourselves even after being cleansed.
The temple and our walk is a promise, the walk has Holiness in it, and if we become unclean, we can repent and be cleansed. Our human culture emphasises class and status which is taken on as if it can be inherited by race, or birth, or our salary, or wealth, or where we live. But God looks are cleansed people, purified Holy people. If this purification was not possible, how could people be anointed with the Holy Spirit and become temples of God.
Part of unbelief is repentance and faith in Jesus and the cleansing of the cross does not purify us as people of the Kingdom. But it takes real faith to see God and the simplicity of this action. Our hearts motivate everything in our lives, and the Lord does change us. Who are we to declare His work is a failure? Who are we to declare what He can achieve or how He looks at us?
What I find hardest to accept is believers declaring the Lord is speaking double speak, or sarcastically, or cannot redeem us truly and lead us exactly in His ways. To declare ourselves perfect would be pride and declaring status, rather than acknowledging it is a walk one step at a time, and everything is always a challenge. Even for Jesus only at the end, when He died on the cross was it finished.
God bless you