The second requirement is to live and remain in a holy life in God's chosen place—Zion and Jerusalem (v. 3a). Today the local church is Zion, and the Body of Christ is Jerusalem. We must live and remain in the church to live a holy life. This is a condition for our partaking of Christ.
Third, we must be chosen by God according to His record of life (v. 3b). Our being chosen by God qualifies us to partake of Christ.
Fourth, the filth should be washed away and the bloodstains should be cleansed away by the Lord with His judging and burning Spirit (v. 4). The judging and burning Spirit should work within us to wash away our filth and to cleanse away our bloodstains. We "kill" the saints through our gossiping and spreading of rumors. We need the judging and burning Spirit to cleanse us inwardly from these bloodstains.
The age of grace is a foretaste of the age of restoration; hence, the above requirements are also the conditions for the believers to partake of Christ in the New Testament economy. The age of grace is a foretaste of the age of restoration, and we are the people who can enjoy such a foretaste. We have the privilege of partaking of Christ if we meet the requirements, the conditions.