"Whoever transgresses and does not abide in the doctrine of Christ does not have God.  He who abides in the doctrine of Christ has both the Father and the Son" (II John 9).

John first informs us, that we are involved in sin, when we don't abide in the doctrine of Christ.  Our Father wanted to have sons and fellowship with them before the foundation of the world.  That is why he chose in Christ before the foundation of the world (Eph. 1:4). Even before Satan was created, our Father foreknew that Satan would fall into sin and disobedience.  Even before Adam was created, our Father foreknew that Adam would be deceived by Satan and would also fall into sin and disobedience.  Our Father chose us in Christ in order that we would be saved and preserved as His eternal sons with the imputed righteousness and holiness of Christ by being eternally placed in Him.  It is a sin and a slap in the face to our Father for us attempt to live any life independent and separate from Christ.  Sin is where we attempt to live independent from God in any manner, either before or after salvation takes place in us.

John also declares, that when we don't abide in the doctrine of Christ, you don't have God.  There are many Christians who claim that they know God.  I am sure that they may know God to a degree in various ways.  However, let's get serious and down to the bottom line on truth.  When we don't abide in the doctrine of Christ, we don't have the Father's attention. The Father loves the Son.  The Father is well pleased in the Son.  The Father has centered, focused, and revolved His entire eternal plan around His Son. Perhaps, we may need to be sure we know what the doctrine of Christ is.  The amplified Greek text reads, that "many deceivers have gone our into the world who do not confess Jesus Christ is ever coming in the flesh.  This is the deceiver and antichrist" (II John 7). There is very few who would deny that Jesus Christ came in the flesh in the Mary body as Jesus of Nazareth (John 1:14).  However, there are a great number of Christians who do not regularly confess, discuss, or even talk about Christ in them as their life and expression.  They still think they are living a life apart from Christ, even after salvation.  The doctrine of Christ is that Christ is still coming in flesh through every member of the many-membered body of Christ to express His life and the will of the Father (Gal. 2:20).