One: believing in and following after Jesus is essential to a relationship with God, purpose in this life, and eternal life to come. This is hindered by our bad choices which the Bible calls sin. Jesus offers us a gift, forgiveness and restoration, that can't be earned by being a "good person." We receive this gift by putting our full weight (think faith) in Jesus alone for salvation. We do not nor cannot merit this gift. It is given by grace, the unmerited favor of God.
Two: that involvement and membership in a local group of people who are also following Jesus is central to a growing relationship with Him, ourselves, and others. This is not being a fan, church is not a spectator sport, rather it is being the church, a people that has places to meet, but are not the places themselves.