We glean from Mk 8:27-31 that authentic discipleship requires two qualities:
Firstly, Disciples Are to Have a Sound Knowledge of the Identity of the Lord Jesus Christ.
Secondly, Disciples Are to Have a Thorough Understanding of Christ's Messianic Mission.
As we look at the remaining verses, Mk 8:32-9:1, we find that authentic discipleship demands at least a third requirement: Disciples Are to Make an Ultimate Commitment to Messiah's Path.
Mk 8:32 tells us that Jesus spoke very plainly, that is in unveiled terms, with his disciples concerning the climax of his ministry, i.e., his suffering and death at the hands of the religious leaders of Israel. The disciples were so staggered by his prediction that Peter took hold of him by the hand, led him aside and began to contradict and censure him. Matthew records the harsh words of this apostle: ".. Far be it from you, Lord! This shall never happen to you." Mt 16:22.
Our Lord acted very promptly, swiftly and forcefully against this impudence. He rebuked Peter and demanded of him, "Get behind me, Satan! For you are not setting your mind on the things of God, but on the things of man." Mk 8:33. This stinging rebuke suited Peter's comment because of the latter's intent: its essence was the dissuasion of our Lord from going to the cross, the very purpose of his mission and the climax of his Messianic work. Peter's remark reminded our Lord of the wilderness temptation by Satan who promised him the kingdoms of this world if he would fall down and worship him, Mt 4:8-9. There, Jesus’ severe reproach included some of the very words he employed against Peter "Be gone, Satan! For it is written, "'You shall worship the Lord your God and him only shall you serve.'" v. 10.
Peter’s remark therefore was not simply a matter of an enthusiastic disciple's reluctance to see his Master depart in pain and death. Far worse than that, it was a satanic attack against Christ's Person and work as God's appointed and approved substitutionary sacrifice of sin. Though motivated by different reasons, Peter and Satan had this in common – the desire to diverge Jesus Christ from the cross, that is, from his divinely appointed mission. Not only was Peter equated with Satan but also he was told that his thoughts were not centered on God's purposes but on earthly matters, on the things of man. In other words, his attempt to dissuade Christ from going to the cross stemmed from a perverted, fallen human perspective.
What does our Lord next do? He soberly reassures the entire gathering that discipleship is very demanding; he gives them the third requirement of authentic discipleship – a faithful following of Christ, even to the point of death. Such a commitment consists of two aspects: firstly, a once for all break with the past by a radical self-denial and by taking up one's cross, in other words, a resolute rejection of all inclinations opposing Christ's purposes and a willingness to accept the ultimate humiliation for Christ's sake; and secondly, the habitual walking in the path of Christ.
The controlling principle of this commitment is this: those seeking to gain eternal life by living according to worldly patterns and pleasures will lose it but those unreservedly devoting themselves to Christ and his gospel will gain eternal life. This requires no thought because the soul is the most important aspect of our being; its value surpasses all the wealth of the world. The man possessing prosperity, fame and prestige who dies in an unregenerate state forfeits his soul for which no earthly equivalent can be found. True disciples therefore are to proclaim and defend Christ unashamedly in this "adulterous and sinful generation" knowing that such faithfulness will be justly rewarded when Christ comes the second time in all his glory. The opposite of this is also true –those who are unwilling to undergo all forms of humiliation for the sake of Christ in today's world, of them "will the Son of Man also be ashamed when he comes in the glory of his Father with the holy angels." Mk 8:38. This word is true; some of them hearing his voice will soon have a preview of his glory at his Transfiguration, on the day of Pentecost and at his Ascension.
Here we have three un-negotiable requirements of a disciple of Christ: an accurate knowledge and confession of his Person; a thorough understanding of his Messianic work; a complete commitment to walk in the perilous path he lays out for us, knowing that faithfulness in this world will be abundantly rewarded at his eschatological appearance. The question that challenges us today is this: are we living like condemned men and women whose joy is reserved for us in heaven or are we combining overt religious activity with vile self-centeredness in order to have the best of both worlds? Are we wholehearted followers of Christ or are we yes/but Christians- yes, I believe in Christ, yes I believe that we have to give up all the follow him, but after all, we have to be responsible and realistic "to do what we have to do" in order to get by in this dog-eat-dog world. Where do you stand?