1 My little Children, these things I write to you so that you do not sin. And if anyone sins, we have an advocate with the Father, Jesus Christ the Righteous. 1 John 2:1 (translated from the NA28 Greek text)
Perfection is not for anyone is this life. The only perfect person who ever walked this Earth was the Lord Jesus Christ and the reason He could be perfect and was perfect is that He is deity. Part of His mission was actually to perfectly keep the Law in order to be the propitiation and only acceptable sacrifice in the Father’s eyes in place of those He came to save. We see this in the following verses.
2 And He is the propitiation for our sins, not for our sins only, but also for the whole world. 3 And this we know that we have known Him, if we keep His commands. 4 The one saying, “I have known Him” and he does not keep His commands is a liar and the truth is not in him. 5 But whoever keeps His word, truly in this one the love of God has been perfected, by this we know that we are in Him. 6 The one claiming to abide in Him ought to walk as He walked. 1 John 2:2-6 (translated from the NA28 Greek text)
What is an advocate? I translated the noun παράκλητον as “an advocate” in v1. Here it is the Accusative, Singular form of παράκλητος (paraklētos), “one who is called to someone’s aid; i.e. counselor, helper, advocate.” In 1 John 2:1, the context of παράκλητος is to the Father on our behalf for the occasions when we sin. John depicts Jesus in this role. As Christians, we can feel confident that Christ will never leave us. Jesus Himself takes up the cause of believers in the presence of God the Father. Otherwise, their sin would bring judgment upon them.