Fellowship with God is vital to the operation and performance of our faith in Christ. Fellowship is not an assumed state of being, rather, it is an active state of being. Just as a husband and wife. married though. but may not be in fellowship with each other for reasons best known to them, a believer can be out of fellowship with God, (though he is in Christ and born again) for the reason stated in 1John 7:5-7
"This then is the message which we have heard of him and declare unto you that God is light and in him there is no darkness at all. If we say we have fellowship with him and walk in darkness, we lie and do not the truth. But. if we walk in the light as he is in the light, we have fellowship one with another; and the blood of Jesus Christ his Son cleanses us from all sins.”
The Word tells us that walking in darkness is inconsistent with walking in the light. Walking in the light is walking according to God's Word; it means for one's steps to be ordered in the Word, and that is what it means to be in fellowship with God. Therefore fellowship with God must not be assumed; it is a walk with God, a walk of faith, a walk of keeping pace with God in the Word. That you are born again does not necessarily mean you are in fellowship with God. You must learn to put the Word to work in your life. You must turn on the switch of fellowship with God by acting upon the Word; You must seek to keep faith and union with the Word daily. Fellowship with God is staying in faith and union with the Word daily.
Note what the Bible says in verse 6 of 1 John 1; "if we claim or say that we have fellowship with God, and walk in darkness, we lie and do not the truth." But, in verse 7, it states that if we walk in the light...” showing that being born again does not necessarily translate into walking with God; they are two different things. Being born again is the prerequisite to walking with God. A walk is an active state of being. and you have a part to play; you have a responsibility to discharge. it is very important you know what it is. So, in a walk with God, there are things to do, and as you do those things in faith, you come into fellowship with God. You live daily by the Word. When you stray. repent and pick up yourself from the dust. receive forgiveness and press unto perfection. God is faithful to perfect what He began in you. Trust in Him with all your heart. and lean not on
our own understanding.