A man who claims to be righteous in Christ yet makes no effort to pursue a life of righteousness is, at best, self-deceived. Likewise, a woman who claims to love all Christians everywhere but does not love her Christian sister is likewise self-deceived. Both are hypocrites. They are nominal Christians––Christians in name only––because their profession does not translate into action or reality. They claim a positional status before the throne of God, but nothing in their lives commends the reality of that status, as if God were a fool who could be mocked (Gal. 6:7). Their faith is without works, which, James tells us, is a dead faith. It’s meaningless. It’s hot air, even if they think that they really, really mean it. The kingdom of Christ is about reality––a new reality, not the illusory old one.
So too with one who claims to belong to the church without belonging to a church. I fear that he looks very much like a nominal Christian and a hypocrite.
–Jonathan Leeman, The Church and the Surprising Offense of God’s Love (p. 214).