Ultimately it is Personal
God is working in the world through His children gathered together and working together - as local churches. Local churches are made up of individuals. While is not a solo affair, Christianity definitely has a very personal aspect to it. For a church to be healthy, for you to be part of something bigger than you, you need to make some important decisions for yourself and how you are going to live. Jesus extends the offer, "Follow Me." Who is this Jesus?
Colosians 1:19-22
For God was pleased to have all his fullness dwell in [his Son], and through him to reconcile to himself all things... by making peace through his blood, shed on the cross. Once you were alienated from God and were enemies in your minds because of your evil behavior. But now he has reconciled you by Christ's physical body through death to present you holy in his sight, without blemish and free from accusation.