Do I have to?
Yes, you have to. There are those who say, "I can worship God anywhere," and so refuse to become part of a community of believers. While it is true we can lift our hearts to God wherever we are, that doesn't replace our responsibility to regularly attend a church.
Not forsaking our own assembling together, as is the habit of some, but encouraging one another; and all the more as you see the day drawing near. (Hebrews 10:25)
What is the purpose of being a member of a church? It is a constant reminder
that you are part of Christ's invisible church. It is a place where you can find encouragement through joining in worship, praise, and prayer with other Christians. There you can connect with mentors to aid you in your spiritual walk, as well as be an encouragement to other believers. You can be challenged by sermons and Bible teachings from Spirit-anointed speakers. And you can be part of the work of redemption by doing your part to reach others through the medium of the church's outreach programs.
It is also a place where you can be initially baptized in water, as well as regularly take part in the Lord's Supper celebration, which is where believers share bread and the fruit of the vine in remembrance of Christ's sacrifice on the Cross.
But... there's a problem. Finding a good church in this day and age isn't easy. There has been a tremendous drifting away from the pure message in the last century. Denominations that once stood firmly for the truths of God's Word have become little more than social organizations. Other churches seem more focused on entertaining their members than in grounding them in solid Christian teaching. The call to personal holiness is rarely heard. Behaviors not conducive to healthy spiritual lives are no longer proscribed. People are encouraged to believe that God's grace covers them in such a way that it hardly matters how they live so long as they show up for church once in a while and make a weak profession of faith.
And we were just encouraging you to attend church? Yes, we are, because that is what God wants. So pray for divine guidance. He will lead you to a church. It won't be perfect, because there are no perfect churches. But you can find groups who are earnestly seeking to walk in God's light. And once you find them, pray again that the Lord will lead you to the spiritual core of that fellowship.
Give yourself to God's service in the church wherever you can, and as He leads, but never let this service become a replacement for true devotion to Jesus Christ. Keep Him in the center, so that He is always the sole focus of your life. Then all you do and all you are will be a blessing to those within and without the church.
Scripture quotations taken from the NASB