Those who claim to believe orthodox doctrine but who do not make conscience of Christ’s commands are missing a vital mark of conversion. The true believer has a strong sense of being under Christ’s authority and has no desire or ability to free himself from it. Evidently it is possible to be deceived about whether we know him.
It is a bad sign when those who claim to belong to Christ cannot be persuaded by clear Scriptural arguments to change some aspect of their lives which is not in harmony with the gospel.
It is possible for the believer to have sure knowledge of his own spiritual state and to know with certainty that he knows Christ. One source of this assurance is the believer’s observation of his own changed character: he has a new settled determination to obey God from the heart.
One has said, ‘Today we are very reluctant to doubt the standing of anyone who has made a profession of faith and holds membership in an Evangelical church … but the apostles were never afraid to suggest that people were unconverted, for they insisted on a continuing willingness to obey the clear commands of God.’