Heb. 10:14 For by that offering he perfected forever all those whom he is making holy.
When Jesus offered himself on the cross as the sacrifice for our sins, something absolutely amazing took place; He perfected all those whom He is making holy. Being perfected is not the same thing as being perfect. No one on earth aside from Christ himself has ever been perfect. It is impossible for us to be perfect. We will never get to the point where we cannot be tempted and then fall into it. Being perfected means that we are completely saved when we come to Christ for our salvation. There is nothing else that can be done for us. Christ completely makes us presentable to God as His children. We are seen by God through the righteousness and holiness of Christ. We are fit for the Kingdom of God.
It is a mysterious and wondrous thing Christ has done for us. No one can fully grasp how amazing it is to be seen by God as perfectly fit to come into His presence. No one can fully grasp how a perfect God can tolerate a sinful man in His presence.
Those who are perfected are those whom Christ is making holy. This is an ongoing process that never stops. We are always being worked on. It is Christ’s mission to make us holy. We cannot have fellowship with Him if we are not letting Him make us holy. He will not change us against our will, but if we are willing, we do become a holy people. If we resist His work within us, we cannot claim to be His children. There is a definite working of God in us that causes us to change if we are indeed His children. We are permanently declared to be perfected when we let the Lord have His way in us.