We talk about faith but it is hard to define. But, faith is how we operate, how we Christians live. Sometimes faith takes place in the dark but it is never irrational. We tread territory sometimes that is so dark and scary that we don’t know if we can go on. But we go on because we trust the One we have placed our faith in. Sometimes we take a leap of faith because God has said to us, trust me.

Remember the movie, Indiana Jones and the Last Crusade? They have found the location of the grail and they are trying to overcome the obstacles. The Nazis beat them there and they are caught. They have reached an impasse as they try to get to the grail, a trap keeps killing those who attempt to go the last few feet. The bad guy, Walter Donovan, shoots Indiana Jones’ father and tells him he has to get the grail if he is to save his father. He has followed the book all the way to this point, the research his father has done. He trusts his father’s research. He comes to one point where there is a great chasm to cross and there is no bridge. The notes say that you must leap. He hesitates and his shot father moans behind him. He says it is a leap of faith and steps out into the air and the is a bridge so camouflaged that it can’t be seen. He trusted his father’s information, he had to take the step.

Walking by faith is something like that. God gives us enough evidence that we trust him. And when we have to walk in the darkness, we take the step because we trust God.

The Pharisees had a faith problem and came to Jesus asking for evidence, for a sign. Jesus did, on occasion, preform miracles. He healed the sick. He fed the hungry and even raised the dead. What more can one ask for? Mark frames this moment with a number of miracles. In the previous chapter, Jesus cast of the demon from the daughter of the Syrophoenician woman. He cured a deaf-mute. And then, Jesus fed the hungry again. He fed four thousand with seven loaves of bread.

Faith requires us to have some information, some proof because faith is not blind. We have to develop trust in people and things if we are going to place our faith in them. God had given them many examples of divine power demonstrating that Jesus was the Messiah who had come to take away the sins of the world.

Yet, the Pharisees came to Jesus and asked for a sign. They did this to test him. In fact, the language is aggressive and hostile. The Pharisees were by no means convinced that Jesus was the Messiah. What they wanted was to see one of those miracles that everyone talked about. But, they demanded that the sign be from heaven. Apparently they were convinced that anyone can feed the poor from seven small loaves of bread, heal the deaf and dumb, cast out demons, control the weather and even raise the dead. None of these things rated as a sign from heaven for them. They were deliberately, rebelliously cynical about Jesus. They had long ago made up their minds to oppose God in the flesh. He did not conform to their thinking.

Mark says that Jesus sighed deeply in his Spirit or to himself. This word "to sigh" describes deep grief and disappointment. I think it is an expression of divine anger. These were the religious experts, they had great spiritual privileges and should have been more responsive to him. But, they wanted a sign. They were blind and had no intention of accepting Jesus as Messiah. Jesus asked why does this generation ask for a sign. In another text, He calls them an evil and adulterous generation because they refused to believe instead they craved signs. He said that they would not receive a sign. No more signs, they either believe or don’t.

You would have thought that the disciples understood. Jesus left the Pharisees and told the disciples to sail off. They left in a hurry and forgot to take bread. As they discussed this important shortage among themselves, Jesus said to them, "Beware of the leaven of the Pharisees and the Sadducees." It was a warning, it sounded serious.

This whole thing is confusing because this word, "leaven" has two meanings. Leaven is yeast, it is necessary to make bread rise. Leaven was also a symbol or an expression of evil influence. Leaven was an invader and once it was placed into the dough, it infected all of it with its fermentation until the whole loaf would rise. Thus, the evil of the Pharisees was like a little leaven in a big lump of dough, in a little while the whole lump was infected.

The disciples said among themselves, It is because we did not take any bread isn't it. They were confused, they thought Jesus was warning them about bad bread. They were too blind to hear the words of Jesus. His warning was on target, don't let the Pharisee’s beliefs and attitudes infiltrate your hearts or you will become like them. Even though they had ears, they did not hear, they were too worried about their stomachs.

Jesus asks had they hardened their hearts? Don't you remember how I fed the five thousand? And what about the four thousand? Do you not yet understand? Have you not seen enough?

The disciples were having trouble with faith. Their faith was weak. They still followed Jesus. When then left the Pharisees, they entered the boat with Jesus instead of going with the Pharisees. There was trust in Jesus but it was weak and it had not infiltrated their entire being.

Later in this chapter, Jesus asks the disciples "who do men say that I am?" They gave the various answers, John the Baptist come back to life, others say Elijah or one of the prophets.

"But, who do you say I am," he asked. Peter answered, "You are the Christ." Faith was deepening. In fact, Peter was believing things he did not yet understand. In Matthew Jesus is recorded as saying that "Flesh and blood did not reveal this to you but my Father in heaven." Now we know that faith has a God givenness to it. We don’t really have faith until God gives it to us. But, we still have to exercise it. We have to actively live by faith.

Faith is a practical trust in God. We are called upon to place our lives in the hands of God and to follow his will. Faith focuses on the practical trust in the power of Jesus to meet our needs. Whatever Jesus says, is done.

In scripture, faith is the only way of knowing God. It recognizes That Jesus has the authority to heal and to save and to provide for his people. Faith is also the essential basis for belonging to the people of God. It is how we are saved. And furthermore, faith is the distinctive characteristic of God's people. We who call ourselves Christians are to be marked by our faith in Christ. It was exactly the quality that was lacking in the Pharisees.

Living by faith is not so mysterious. We know God, we have experienced him. We trust him because he has proven himself to us. That faith might be only a tiny flicker for some, one that is not mature and still does not see well. But, each day with Jesus we grow stronger in faith because we learn to trust Jesus in all things. Our experiences with Jesus cause our faith to grow. This is why it is imperative to have a prayer life and to be committed to public and private worship and Bible study. We must spend time with Jesus. And we must spend time with each other. Often, we will see Jesus in the actions of our fellow believers.

Sooner or later, we find ourselves in a world that is dark and sinister and perilous. Things happen to us and to your brothers and sisters in Christ, serious illness, troubles, misfortunes, and we wonder how will we ever make it. This chasm is so large, how can we ever cross it? But, Jesus said "follow me." Faith demands that we let go of our doubts and fears and follow.

It is a call to faith. We take the leap, we step off the ledge, we walk into the darkness because we trust Jesus. That is when our faith becomes alive! We walk into the darkness, with ears that hear, following the voice of our Shepherd. We know that he will not mislead us. He will be faithful to us and he take us home.