He that saith he abideth in him ought himself also so to walk, even as he walked. Abideth in him - He who not only professes to have known Christ, but also that he has communion with him, and abides in his favor, should prove the truth of his profession by walking as Christ walked; living a life of devotion and obedience to God, and of benevolence and beneficence to his neighbor. Thus Christ walked; and he has left us an example that we should follow his steps.
To be in Christ, 1 John 2:5, is to be converted to the Christian faith, and to have received the remission of sins. To abide in Christ, 1 John 2:6, is to continue in that state of salvation, growing in grace, and in the knowledge of our Lord Jesus Christ.