How do you get to be in Christ? How do one get to be in Christ? Is it same as to be righteous before God? I consider Romans 8:1 as axiom. 


  Therefore, there is now no condemnation for those who are in Christ Jesus,
That little word in is packed with profundity, significance, and comfort for believers in Jesus Christ.  

One way of approaching this little word is via one of the many names for the Church Universal:  the Body of Christ.  A body, of course, is composed of many parts (viz., appendages and external and internal organs), and so it is with Christ's body, the church, of which He is the Head.  All of the parts of the physical body are in the body and are thus joined to the whole body.  Each part has its function, but they all function together.  The main point of the analogy of the body can be summed up, I feel, in the expression


  "Unity within Diversity."


To be in Christ, then, is to be a part of His body.  

Theologically, the word in signifies where a believer is, positionally in the eyes of God; namely, in Christ.  To be in Christ is to be united with Christ in His righteousness.


  "For God made Him who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him" (2 Corinthians 5:21, my emphasis).


We who are sinners saved by grace are anything but righteous.  Moreover,  Isaiah tells us that 


  "For all of us have become like one who is unclean, And all our righteous deeds are like a filthy garment; And all of us wither like a leaf, And our iniquities, like the wind, take us away" (64:6). 


In other words, even the best we have to offer God cannot outweigh in the divine scale of justice our uncleanness, filthiness, and iniquities.  Along comes Jesus, however, and His righteousness tips the scale in the opposite direction, so to speak.  

Think of a zillion-pound weight being on one side of the teeter totter.  That's our sin.  Our righteous deeds piled up to the sky on the opposite side utterly fail to budge the zillion-pound weight one scintilla. 

Jesus' cross death, however, means that God, when He imputes our sin to Jesus and then in turn imputes Jesus' righteousness to us when we believe, tipped the teeter totter as far as it can go in the opposite direction, as if the zillion-pound weight were but a feather!  Aren't you glad you're in Christ?  There is no safer place to be in all the universe, because when God sees us, He sees us in His Son.  And as Paul reminds us,


  "Whoever is in Christ is a new creation:  the old has passed away, and all things have become new" (2 Corinthians 5:17, my emphasis).