Perhaps the best way to answer this question is to have a true understanding of what “church” is. In asking if God is everywhere and if we can pray in our homes and ask for forgiveness there, the answer to both would be yes. This is shown by Christians whom are bedridden or otherwise unable to attend church. However, this is not the norm and not how God designed church to be. In fact, in the book of Hebrews God tells us directly to make sure we are involved in a church.
Although the church has many functions, I’d like to focus on just two of them. The first reason one should go to church is for the fellowship with other believers. Let’s face it; it’s tough to live on this planet. With all the problems that face us there are going to be times we will need to depend on other people. Likewise, in good times for us, there will be other people who will need to depend on us. This is the function of the church. To be a place where Christians can come together to help and encourage one another while learning more about God.
The other function of the church is that of holding each other accountable for our lives. You see, when we give our lives to Christ it is real easy to live a “moral life” for a short time. However, there will be times when it isn’t so easy. During these times that it isn’t so easy, we can lean on people in the church to help hold us accountable to making good choices. Think about your own life; let’s say you were tempted to cheat a little on your income tax report. If you knew for a fact that the IRS was going to be asking you the very next day if you cheated or not, would you still do it? Most likely not. It works the same way in the church when we develop friendships with other Christians who can help us to make sure we are making the right choices.