William Burkitt on Matthew 19:21

That is, "Thou hast been all thy days a Pharisee; if now thou wilt be a Christian, thou must maintain a readiness and disposition of mind to part with all that thou hast in this world, at my call and at my command, and follow after me."

Learn, That such as enter themselves disciples of Christ, must be ready, at Christ's call, to part with all, for Christ's sake, that they have in this world.

2. All that profess themselves to be Christ's disciples, must be his followers; that is, that they must obey his doctrine, and imitate his example, his holiness, his humility, his heavenly-mindedness, his patience, his meekness, his readiness to forgive injuries; and the same mind must be in us which was in Christ Jesus.