The pressure of the Pharisees' example, along with the rise of persecution, prompts Jesus to warn his disciples about whose opinion they value. Peer pressure is a given in any culture. The power of those who seek conformity is very strong. Persecution methods can be strong, controlling and painful. The book of Acts tells of beatings, floggings and stonings. Economic pressure was also sometimes applied, along with social ostracism. The pressures to conform are still great. But Jesus issues a call in this passage to be strong and resist such pressure.
In the midst of growing crowds and official opposition Jesus issues a warning. The setting of his words is not insignificant. Even though people are practically crawling over one another to get to Jesus, the disciples should not be fooled by current popularity and should recall the level of opposition Jesus has faced. Popularity can breed a desire to remain popular and thus to soften the hard truth of our sinfulness before God. So Jesus warns, "Be on your guard against the yeast of the Pharisees." Leaven (NIV yeast) was a symbol of corruption (Ex 12:14-20; 1 Cor 5:6). The Pharisees' hypocrisy has just been discussed in 11:39-41. Jesus is saying that the desire to impress can lead to a double life. The way of the Pharisees is not the way for Jesus' disciples.
Hypocrisy will not work, because everything is revealed before God. The secrets of people's hearts will be revealed (Rom 2:15; 1 Cor 4:5). God's omniscience means that there is nothing concealed that will not be disclosed, or hidden that will not be made known. This includes words said in the dark or whispered in private rooms. A private room (tameion) was the innermost apartment in a house. So even things said deep within one's home and mind are known to God. Even these things will be proclaimed from the housetops one day. What is done in the basement will be revealed on mountaintops. We may divide our activities into public and private, visible and unseen, but there is no such division with God's vision. The walls we build up to protect our psyche and rationalize our behavior cannot keep out the eyes of God.
Now we might debate whether the passage stresses the revealing of sin or the exposure of righteousness. The previous statements about hypocrisy make a negative force likely here, but the following call to fear God may also suggest that God's positive response is in view. The choice between the options may be a false one. God responds to all that we do, and his justice in the future will balance any injustice that exists today.
So given the pressure to do one thing in public and another in private, Jesus reminds the disciples that they should fear God. They should fear not those who kill the body but the One who has power to throw . . . into hell. Human beings' power over life is limited. The life that counts is the life to come. We should not fear rejection or even martyrdom. The Jews understood this as well: "Let us not fear him who thinks he kills; for a great struggle and peril of the soul awaits in eternal torment those who transgress the ordinance of God" (4 Maccabees 13:14-15). There is no prosperity theology here, nor is there any glossing over of the rejection disciples may face. Standing up for God will mean opposition; they had better be prepared.
But they can also be assured that God is aware of their situation no matter how bad it gets. Even five sparrows that sell for a few pennies do not escape God's attention. These sparrows were the cheapest thing sold in the ancient market, and an assarion (Greek form of a Latin loanword) was the lowest valued Roman coin, being worth one-sixteenth of a denarius or a half-hour's minimum wage. God cares for those insignificant birds, and he cares for the disciple. He knows the number of hairs on one's head, and he knows that people are more valuable than sparrows. So we need not fear even the direst of persecutions, because God knows what is taking place.
What it all comes down to is a choice of allegiance, an identification with Jesus. Those who acknowledge Jesus before human beings will receive due reward. The Son of Man, that is, Jesus, will acknowledge them before the angelic witnesses of heaven; they will stand accepted for eternity. A picture of this truth is Stephen's martyrdom in Acts 7:54-59. On the other hand, those who deny Jesus will face a similar denial before the angels.
Jesus raises the issue of blasphemy against the Spirit, a sin that cannot be forgiven in contrast to a word spoken against the Son of Man. This statement has led to considerable debate. Is the blasphemy attributing Jesus' work to the power of Satan (11:14-20)? Is it a reference to apostasy? Is it rejecting the apostles' preaching about Jesus, since that was Spirit-empowered preaching? Or is it not so much a single act as a persistent rejection of the Spirit's testimony about Jesus? This last option, the obstinate rejection of Jesus, is the most likely meaning. Not only does this remark fit all the Synoptic contexts in which this saying appears, but it fits with the importance Jesus places on the preached gospel message (Lk 24:44-47) and corresponds to the warnings the apostles issue at the end of their preaching (Acts 3:22-26; 13:38-41). To fear God means to choose Jesus. To reject him is to reject the Spirit who testifies constantly to him. Exposure to Jesus and church attendance are not the same thing as receiving the testimony of the Spirit and embracing the hope of the gospel. The Son of Man accepts only those who respond to the testimony of the Spirit (1 Cor 2:14-15).
Jesus' remarks prepare anyone thinking about responding to him for a world that will pressure those who embrace Jesus. The world may persecute disciples, but Jesus will honor those who seek him.
The pressure to deny Jesus may be great, but so is God's provision as disciples stand up for him: "When you are brought before synagogues, rulers and authorities, do not worry about how you will defend yourselves or what you will say." Jesus promises that the Spirit will come to their aid. Again, examples of fulfillment of this promise occur in Acts (4:13-22).
The disciple may face a hostile world, but loving God means standing up for him. Behind that backbone and resolve to face the opposition is an understanding that we must fear God and know that he sees both the disciple and the accuser. What is done in secret will be revealed in public before God one day. Then the disciple will stand though others fall.