Yes, it's certainly important to believe in Jesus; after all, He gave His life for your salvation. If we ignore or scorn Him, the Bible says we have no hope of eternal life, or even of God's help right now. The Bible warns, "Salvation is found in no one else, for there is no other name under heaven given to mankind by which we must be saved" (Acts 4:12).
But God doesn't want us to be isolated from other believers. They may not be perfect, but we aren't, either. We need each other, and when we cut ourselves off from other believers our spiritual lives are weaker and incomplete.
We need the understanding that comes from the preaching and teaching of God's Word, as well as the love and friendship that grow from fellowship with other believers. God also wants us to serve Him, and a church can provide opportunities for this. The Bible says, "Let us consider how we may spur one another on toward love and good deeds, not giving up meeting together" (Hebrews 10:24-25).
Ask God to help you forgive those who may have hurt you, even as Christ has forgiven you. What they did was wrong, but don't let it cut you off from others in your church who need you. And if it simply isn't possible for you to be comfortable at this church anymore, ask God to lead you to another church where you'll not only feel welcome, but can also grow in your faith.