These things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous – 1 John 2:1
The Christian’s goal, John says quite frankly, is total sanctification -- complete victory over sin in our own life.
John is not satisfied, and neither is the Holy Spirit who inspired him to write these words, with a half-way Christianity. It is not good enough to live a more holy life than your next-door neighbor; it is not good enough to simply avoid the “big” sins like murder or adultery.
No, John insists, my goal for you is for you to completely mortify the sin that so easily besets you. Pride, gluttony, worry, fear, selfishness, lying, and lust should all meet with a zero-tolerance determination in our spirit. We should never be content to allow any sin to set up camp in our heart without consistent opposition and a concerted effort to root it out.
But almost in the same breath John also gives us this blessed reminder, knowing that sin will never be completely defeated this side of the grave: if any man sin, we have an advocate with the Father, Jesus Christ the righteous.
Although we are not righteous, Jesus Christ was perfectly righteous on our behalf. When we sin, we have an Advocate with our heavenly Father who pleads his righteousness on our behalf.
The Christian life, then, is a mixture of dissatisfaction with sinful self and complete satisfaction in the righteousness of Christ. It is striving and resting, improving and perfection.