Luke 17:5-6 5 The Apostles said to the Lord, “Increase our faith.” 6 The Lord said, “If youp had faith as big as a mustard seed, youp might say to this mulberry tree, ‘Be uprooted and be planted in the sea,’ and it would obey youp.”
It is not the smallest seed in Israel or the world, but Jesus is teaching the Jews a truth by illustration. He uses the mustard seed as the smallest domestic, insignificant seed. Most believe this is Brassica nigra. See here for discussion in Jewish Virtual Library.
The Apostles are asking for more faith. They know that faith in God is pleasing to Him.
What is faith? Biblical faith is not a blind faith but is, in fact, faith in evidence (A quote from Is Faith Reasonable).
Why do we need to increase our faith? Doubts? Fears?
Consider some similar passages
B1 Matthew 17:14-21 When they came to the multitude, a man came to him, kneeling and saying, 15 “Lord have mercy on my son, for he is an epileptic and suffers greatly, for he often falls into the fire and often into the water. 16 “I brought him to yours disciples, but they could not cure him.” 17 Then Jesus answered and said, “O unbelieving, corrupt generation, how long will I be with youp? How long will I put up with youp? Bring him here to me.” 18 Jesus rebuked the demon, and he went out of him. The child was cured from that very moment. 19 Then the disciples came to Jesus privately and said, “Why couldn’t we cast him out?” 20 Jesus said to them, “Because of yourp unbelief, for truly I say to youp If youp had faith even as a grain of mustard seed, youp could say to this mountain, ‘Go from here to there,’ and it would change places. Nothing would be impossible for youp. 21 “Nevertheless this kind doesn’t go out except by prayer and fasting.”
B2 Mark 9:25-29 Jesus said to him, “If yous can believe. All is possible to him who believes.” 24 Immediately the child’s father cried out and said with tears, “Lord, I believe. Help my unbelief.” 25 When Jesus saw that the people came running together, he rebuked the unclean spirit saying to him, “Yous spirit who makes him unable to talk or hear, I command yous, come out of him and never enter him again.” 26 [The spirit] screamed, severely convulsed [the child], then came out of him. The child was like one who was dead, and even many said, “He is dead.” 27 But Jesus took him by the hand and helped him up. He got up. 28 When he came into the house, his disciples privately asked him, “Why couldn’t we cast him out?” 29 He said to them, “This kind can only come out by nothing except prayer and fasting.”
Jesus had given a commission and mission to preach the Gospel. They also had been authorized to expel demons (Matthew 10:1-4). The Apostles could not in this case, so Jesus did expel the demon. In response, the Apostles asked Jesus, “Why?” The Lord said, “If youp had faith as big as a mustard seed, youp might say to this mulberry tree, ‘Be uprooted and be planted in the sea,’ and it would obey youp.”
I don’t believe anyone has ever had this type of faith that we commonly associate with the Lord’s statement.
Here are some observations:
B1 Faith is believing God. Believing in the sense of doing. It is not just words but action. See Hebrews 11:6.
B2 Faith is not for our desires and wishes; it is believing and doing God’s will.
B3 Compare
C1 Caleb—Numbers 13:30
C2 Shadrach—Daniel 3:17
C3 Daniel—Daniel 6:10 and Daniel 6:23
C4 Philippian jailer—Acts 16:31-34
B4 Hebrews 11 summarizes many believers to whom God commanded, and they obeyed.
When we read the Scriptures, we read of promises, warnings, and God’s rules. When we believe, then we please God. When we believe, then we live what God teaches. I’ve listed a few examples below.
Rules
B1 Anger—Ephesians 4:26-27
B2 Love enemies—Matthew 5:44. This means to still be kind to enemies and not personally seek revenge. Reporting a crime is not revenge. Jesus lived this verse: Luke 23:34 Then Jesus said, “Father, forgive them, for they don’t know what they are doing.”
B3 Husband to love wife—Ephesians 5:28. This means a choice to live the actions of love found in 1 Corinthians 13:4-8a both in public and private. Words are cheap; it is living these actions daily towards our wife.
B4 And consider the list found in Romans 12:9-21.
Promises
B1 Jesus’s return—John 14:1-4
B2 Forgiveness of sins—Acts 10:43
B3 Jesus will never abandon us—Hebrews 13:5
Doctrine
B1 Jesus is Messiah—Luke 9:20
B2 Deity of Jesus—Philippians 2:5-6
B3 Eternal punishment for those who refuse to believe—Revelation 20:15 and Daniel 12:2
Luke 7:9 When Jesus heard these things, he marveled at him, and turned around and said to the people that followed him, “I say to youp, I have not found such great faith; no, not [even] in Israel.”
B1 Apparently, there are degrees of faith.
B2 Jesus commented on this centurion as having great faith. The man’s prayer was answered.
B3 Jesus commented on the Apostles at the Galilean Lake storm: Matthew 8:26 He said to them, “Why are youp afraid, O youp of little faith?” Then he got up and rebuked the winds and the sea, and there was a great calm.
B4 Jesus mentions ‘great faith’ and ‘little faith,’ but both had their prayers answered.
So, what is important is faith, that is, believing God. God notices great faith and little faith.
No matter what mountain we have or how much faith, have faith in God. The mountain might be illness, pain, sorrow, grief, doubting one’s faith, being poor, difficulties, persecutions, etc. God has mercy and extends mercy. He will not abandon us. He is able to keep us (Jude 1:24-25). Without Him we can do nothing that He asks of us (John 15:5). With Him we can do all that He asks of us (Philippians 4:13). He is able to be with us through our difficulties and challenges (Romans 8:35-39 and 2 Corinthians 1:4). Remember Job, David, Sarah, the Virgin Mary, Peter, Paul, and many others who believed, had faith, lived for God faithful to the end of their lives.
Have faith in God (Mark 11:22). Pray for yourself and others.
1 Corinthians 2:5 So that yourp faith wouldn’t be in human wisdom but in God’s power.
James 1:22 Be doers of the word, not just hearers only, deceiving yourselvesp