God works out His will on this earth through His Church. This is His chosen method of spreading the Gospel message, to demonstrate His great love for humanity, to equip the brethren, to feed the poor, to serve the widow, and to demonstrate His great love by our unity in Christ.
That is why I commented last week that it has always puzzled me when someone thinks it is okay to be a Lone Ranger Christian. They think it is okay to make it a habit of not assembling together and participating in worship and praise to our Lord, they make it a habit to be separate from the Body of Christ as we learn and grow, learn to be more like God. We have been called to participate in God’s work together, to strengthen and encourage one another, to pray for one another. But when we have the capability and wherewithal to participate and we do not, we are missing a big part of who we are as a believer. If we refuse to assemble with the Body of Christ when we are capable to do so, (I believe) it is sin.