They have advanced beyond the need to attend church is deceiving himself/herself and only making excuses for disobeying the command to assemble together in corporate worship:
Why Do I Need To Go to Church?
By Pastor Jack Howell
I often hear people say that they do not need to go to church to worship God. While it is true that God does not dwell in man-made buildings, the simple truth is that we are commanded to attend church. You can read about this at Hebrews 10:25 where we are told not to forsake assembling together for corporate worship of God.
Why do we need to go to church anyway? We need to go because we are designed by God as "relational beings." We spiritually in the context of the relationships we find in fellowshipping with other Christians. It has been pointed out that a Christian lifestyle can be practiced only when it is lived out with other people. In other words, one cannot claim to be a Christian and live the life of a hermit in total solitutude and isolation from others. Only in relationships can we learn how to be patient, loving, giving, or even sacrificial. Even the spiritual gifts God has given to each of us are meant to function in relation to others (1Peter 4:10).
We know from reading God's Word, that He desires a personal relationship with His people, and He wants us to experience that relationship with other Christians. We grow spiritually and encourage one another in "the faith once delivered" (Jude 3) by fellowshipping with one another in a corporate worship setting. We like to think of religion as being a strictly personal matter, and while it is true that God touches each of us individually and uniquely in our spiritual walk with Him, it is but only one aspect of Christian living. As we grow spiritually in our daily walk with Him, we realize a growing need to both find and give support, direction, and interact with other Christians. What began as "I" finds completion in "we."
At Matthew 18:20 Jesus stated that "where two or three are gathered together in my name, there am I in the midst of them." Even though God is no doubt with us individually, Jesus was also saying that there is a unique union He shares with us when we meet together as His church.
It should be pointed out too, that one of the most important functions of the church in our lives is in moving us toward spiritual maturity as I mentioned above. Ephesians 4:11-16 tells us that the goal of church life is to be "built up until we reach unity in the faith...and become spiritually mature." Through this influence of the local body of Believers, we "will in all things grow up unto him...as each part does its work." We may love God and know Him on our own, but we only become complete in Him when we're connected to the life of His church.