Christ Jesus came into the world to save sinners; of whom I am chief. 1 Tim. 1:15.
The purpose for perfection, whatever perfection God has in mind for His children, is to bring honor and glory to Him. Those who obey God bring rewards for His suffering (Thoughts From the Mount of Blessing, p. 89). Those who obey God, and who by His grace understand perfection of character, bring honor to Christ (Christ's Object Lessons, p. 102). Those who obey God bring honor to Christ, because the honor of God is involved in the perfection of the character of His people (The Desire of Ages, p. 671). "Let your light so shine before men, that they may see your good works, and glorify your Father" (Matt. 5:16).
Perfection is not the basis of our salvation. Jesus' death on the cross, accepted on our behalf, is the basis of our salvation. But obedience and Christian perfection bring glory to Him. However, perfection is never apart from God; therefore, we don't bring honor to Him, He brings honor to Himself through us. If it's Christ dwelling within, then He's doing it. Are we going to exonerate God by our holy lives? No--God wants to exonerate Himself by whatever we allow Him to do in our lives.
But we must always remember that the religion of Christ includes more than forgiveness. It includes setting us free from the power of sin here and now. This doesn't mean we will no longer be sinners. Even the apostle Paul admitted that he was the chief of sinners. He wasn't saying that he was sinning all the time. We will join him in that acknowledgment.
Anyone who claims to be perfect or sinless is simply advertising the fact that he's not. We can never claim perfection, because the closer we come to Jesus, the more faulty we will appear in our own eyes. The apostle Paul proved it. "The nearer we come to Jesus and the more clearly we discern the purity of His character, the more clearly we shall discern the exceeding sinfulness of sin and the less we shall feel like exalting ourselves. Those whom heaven recognizes as holy ones are the last to parade their own goodness."--Christ's Object Lessons, p. 160. But although we cannot claim to be perfect, yet as we keep our eyes fixed upon Christ, we can be perfect at every stage of growth.