Matthew 21:20-22 meaning

The parallel gospel account of Matthew 21:20-22 is found in Mark 11:20-24.

Jesus had just cursed a fruitless fig tree and it immediately withered as He was on His way back into Jerusalem (Matthew 21:18-19). His disciples saw this happen and were amazed.

They asked Jesus, "How did the fig tree wither all at once?" (v 20).

Jesus told them it happened because He had faith.

He began His answer with the phrase Truly I say to you (v 21). This expression truly I say to you (v 21) indicated that Jesus was not relying upon the authority of another teacher, as was customary for rabbis to do when they taught. Instead, Jesus was drawing from His own personal (and divine) authority.

Jesus had often taught this way (Matthew 5:18; 5:20; 5:22; 5:28; 5:32; 5:34; 5:39; 5:44; 6:2; 6:5; 6:16; 6:29; 8:10: 8:11; 10:15; 10:23; 10:42; 11:24; 12:6; 12:31; 12:36; 13:17; 16:18; 16:28; 17:12; 17:20; 18:3; 18:10; 18:13; 18:18; 18:19; 18:22; 19:9; 19:23; 19:24; 19:28; 21:43; 23:36; 23:39; 24:2; 24:25; 24:34; 24:47; 26:13; 26:21; 26:34). Jesus's authoritative manner of teaching amazed the crowds (Matthew 7:28-29) and likely offended the religious leaders (Matthew 12:14). The disciples who understood that Jesus was both the Son of God and the Messiah (Matthew 16:16) may have grown accustomed to this by now.

Jesus elaborated upon His answer to His disciples' question that faith in God was what enabled Him to wither the fig tree. He told them, if you have faith and do not doubt, you will not only do what was done to the fig tree, but even if you say to this mountain, 'Be taken up and cast into the sea,' it will happen (v 21).

If they had faith without doubt, Jesus told His disciples, you will not only be able to do what was done to the fig tree (v 21), but will be able to do even greater things than withering a fig tree. He then gave an example of what even greater things looked like.

Even if you say to this mountain, 'Be taken up and cast into the sea,' it will happen (v 21).

The mountain Jesus was likely referring to was the Mount of Olives. It was the mountain they were passing over on the way into the city when Jesus said, "this mountain." The Mount of Olives is a hill of rock that stood roughly 300 feet above the elevation of the temple area and was about 30 miles/50 kilometers from the shore of the nearest sea—the Mediterranean.

Incidentally, or perhaps not so incidentally, this mountain will have amazing things occur upon it and it will undergo an astonishing transformation when Jesus returns a second time. The Mount of Olives was the mountain from which Jesus the Messiah would later ascend to heaven after He came back to life from the dead (Acts 1:9-12). It also will be the spot at which He will return to earth when the Messiah comes the second time (Zechariah 14:1-8). According to Zechariah's prophecy, something equally spectacular (as it being thrown into the sea) will happen to this mountain the day Jesus returns to earth.

"In that day [the Messiah's] feet will stand on the Mount of Olives, which is in front of Jerusalem on the east; and the Mount of Olives will be split in its middle from east to west by a very large valley, so that half the mountain will move toward the north and the other half toward the south."
(Zechariah 14:4)

But Jesus was not teaching His disciples how to perform dazzling feats to impress others. He was training them for how to accomplish the great works that He had created and prepared for them to do (Ephesians 2:10). He was instructing them how to overcome by faith the obstacles they would face while following Him. Some of these obstacles would be mountain-sized, and only by faith could they move it.

Christ's response of faith and do not doubt is very similar to what James wrote when he taught how we are to ask God for wisdom and perspective.

"But if any of you lacks wisdom, let him ask of God, who gives to all generously and without reproach, and it will be given to him. But he must ask in faith without any doubting, for the one who doubts is like the surf of the sea, driven and tossed by the wind. For that man ought not to expect that he will receive anything from the Lord,  being a double-minded man, unstable in all his ways."
(James 1:5-8)

The case of this passage from James 1, the context about asking for wisdom concerns asking for wisdom regarding how to choose to be joyful in the face of difficult circumstances. Having the faith that all God allows into our lives is for our best provides us with a firm foundation to navigate the difficulties of this life.

After Jesus told His disciples the need to have faith and do not doubt (v 21) in order to accomplish great things, He added: and all things you ask in prayer, believing, you will receive (v 22). He was stressing the central role of faith in prayer and our petitions to our Father in heaven. This is similar to what Jesus taught His disciples in the Sermon on the Mount.

"Ask, and it will be given to you; seek, and you will find; knock, and it will be opened to you. For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened."
(Matthew 7:7-8)

When we pray, we are to do so believing that God loves us, believing that He is listening to us, and believing that He will respond to our petitions in a way that serves our best interest according to His omniscient judgment. Praying with believing hearts is one way that we can know God by faith. Knowing God by faith is a path to our greatest possible fulfillment in this life.

In Mark's gospel account, when Jesus explained these things to Peter, Jesus also included the "mercy principle" in His explanation. The mercy principle is this: within His kingdom God gives us the same measure of mercy we give to others. The mercy principle is one of Jesus's central pillars in His kingdom platform (Matthew 5:7; 5:44-47; 6:12; 6:14-15; 7:1-2; 7:12; 18:21-35). The mercy principle is a primary motivation for us to follow the second greatest commandment, which is to love our neighbor as we love ourselves (Leviticus 19:18; Matthew 22:39). And because of the mercy principle, when we love our neighbor, we are also doing what is in our own true self-interest, as illustrated in this passage from Mark 11:

"Whenever you stand praying, forgive, if you have anything against anyone, so that your Father who is in heaven will also forgive you your transgressions.  But if you do not forgive, neither will your Father who is in heaven forgive your transgressions."
(Mark 11:25-26)

Mark 11:25 is similar to what Jesus taught in the Sermon on the Mount about remembering an offense you've done against your brother while sacrificing at the altar (Matthew 5:23-24). Mark 11:26 is identical to what Jesus said in Matthew 6:15. When we treat others as we want to be treated, God promises to treat us the way we desire to be treated.

The mercy principle is not to be confused with our belonging to God's family. Being born into eternal life is on the basis of a person's belief in Jesus as God's Son and as their Savior (John 3:14-16). This salvation from the penalty of sin is a free gift, and is entirely and eternally granted on the basis of God's grace, and not our attitudes or behavior (Ephesians 2:8-9, Romans 11:29). We receive the gift of eternal life by faith. It only takes enough faith to look upon Jesus, hoping to be delivered from the deadly venom of sin (John 3:14-15). God decides how much faith that is.

The mercy principle applies to kingdom living. It affects our fellowship with God and with others in His kingdom. It does not affect our relationship as God's children. There is nothing we can do to make God love us any more or any less, and God never rejects His own. But we can gain His approval or wrath, and the consequences that attend each, based upon how we follow Him by faith or disobey Him by following our own way. The main way we please God is by trusting Him that it's is in our best interest to love other people through serving them and forgiving them. That is difficult until we set aside self. We are prone to execute judgment on others, and seek justice from our own sense of right. But when we leave that to God, and trust that His ways are for our best, God promises to reward us greatly. A significant part of that reward is a much more flourishing experience in this life.

Jesus consistently teaches that within His kingdom if we show mercy to others, we will be given mercy from God. And if we don't show mercy to others, God will not grant mercy to us. It is worthy of reflection to consider that our rewards from God will largely be a reflection of the benevolence we wished upon others. The mirror image of this principle is the fact that God's wrath is revealed against unrighteousness by giving people over to their own desires, and the resulting natural self-destructive consequences (Romans 1:24, 26, 28). It seems that in the end, we all get as our reward what we desired for ourselves and what we wished upon others. If we desired to know God by faith and love others, we gain the greatest possible fulfillment available from living this life.

Jesus's inclusion of the mercy principle in His teaching about how faith without doubt can move mountains and wither fig trees suggests that it takes faith to forgive other people. Sometimes acts of forgiveness and mercy seem colossal to us. In the landscape of human relationships, forgiveness is the only thing that can move mountains of offense, hurt, and bitterness. And great acts of forgiveness require us to have faith in God's love and to not doubt that it is in our best interest even to forgive as we have been forgiven, and to say to this mountain of bitterness "Be taken up and cast into the sea!" (v 21). And if we do this it will happen. And all things you ask in prayer, believing, you will receive (v 22).