The New Testament knows nothing of the lone Christian—the man who claims to be a believer but who deliberately or carelessly allows himself to drift from the local church. Just as the wolf will prowl outside the flock of sheep, looking for the one that strays from the shepherd, Satan prowls the church, looking for the people who stray from Christian fellowship. Every Christian is dependent upon the local church and we neglect it to our peril, for it is in the church that we powerfully experience the means of grace God gives us—the Word, prayer and the sacraments (or ordinances). We cannot thrive or even survive without them. Neither should we expect to.
It is also within the church that we uniquely experience the joy of imitating Christ in putting aside our own desires in order to love and serve others. And so, my brother, don’t simply go to church: Be an active, serving, participating member of that church. Do not expect that you will be able to put sin to death or to pursue holiness without the local church.
~ Tim Challies