The Bible does not give us a clear answer. On the one hand, Jesus is quoted as saying that "the gates of hell shall not prevail against [his] church" (Matthew 16: 18). On the other hand, He warns his disciples that they will lose their life if they do not have allegiance to His 99% (Mark 9:33-37). Ultimately, it appears that church attendance is not absolutely necessary for growing in relationship with Jesus. However, we can certainly benefit from fellowship with believers and learning about God's word.