I love the book of Ephesians! It is one of my favorite books. What is really cool is that the first half of Ephesians brings us Justification, which is me in Christ, my deliverance from the penalty of sin and is my title to heaven. The second half of Ephesians transitions into sanctification which is Christ in me, my deliverance from the power of sin, and is my fitness for heaven.
Here are some of my favorite passages in the first part of Ephesians, illustrating the me in Christ idea.
Blessed [be] the God and Father of our Lord Jesus Christ, who hath blessed us with all spiritual blessings in heavenly [places] in Christ: According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love: Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will, To the praise of the glory of his grace, wherein he hath made us accepted in the beloved. Ephesians 1:3-6
That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; [even] in him: Ephesians 1:10
But God, who is rich in mercy, for his great love wherewith he loved us, Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;) And hath raised [us] up together, and made [us] sit together in heavenly [places] in Christ Jesus: Ephesians 2:4-6
In the above verse, not only do we see the in Christ idea, but we also see that grace saves us from more than just death. It saves us from our sinful lifestyle.
Now we see Paul transition to Christ in us. Below is one of my most favorite passages in all the Bible. It tells us, that not only do we have Christ (God) in us, but we can be filled with all the fullness of God! That is powerful!
For this cause I bow my knees unto the Father of our Lord Jesus Christ, Of whom the whole family in heaven and earth is named, That he would grant you, according to the riches of his glory, to be strengthened with might by his Spirit in the inner man; That Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, May be able to comprehend with all saints what [is] the breadth, and length, and depth, and height; And to know the love of Christ, which passeth knowledge, that ye might be filled with all the fulness of God. Now unto him that is able to do exceeding abundantly above all that we ask or think, according to the power that worketh in us, Unto him [be] glory in the church by Christ Jesus throughout all ages, world without end. Amen. Ephesians 3:14-21
I encourage you to study the book of Ephesians and see what treasures you find!