It is time for some basic Bible study. Thank God for His Word, and walk with me through two somewhat difficult passages.

In Matthew 17:10 (cf. Mark 9:17-29 & Luke 9:38-43a) and then in a separate incident in Luke 17:6, Jesus responds to His disciples by talking about faith the size of a mustard seed. What does “faith like a mustard seed” refer to?

Matthew 17:14-20  (Same event recorded with additional details in Mark 9:17-29 & Luke 9:38-43a)

Basic Observations

  1. Narrow context of the twelve disciples
  2. It was the lack of faith on the miracle-worker’s side that was the problem, not the lack of faith in the sick man and his family
  3. The disciples already had the authority and ability to heal (Cf. 10:5-10)
  4. It appears to be a rebuke for not doing what should have been done, not a promise to be able to do more.
  5. Who is the “faithless” generation of v17? v20 exposes the disciples as the primary target! (Secondary target is the father according to parallel passages, although it is a faith in Jesus, not in healing)


“Faith like a mustard seed” in this event appears to point to the reality that even the smallest amount of faith is sufficient for all the great things the Lord Jesus required of his disciples.


Luke 17:3-6

Basic Observations

  1. Broader context of “your brother”
  2. Forgiveness is clearly commanded in v3
  3. In v5, the apostles clearly recognise the difficulty of such obedience regarding forgiving one another and therefore ask for the faith to do so
  4. Jesus says in v6 that a wee-tiny amount of faith can do anything.


“Faith like a mustard seed” in this event refers to the reality that we need not pray for increased faith to forgive others, for even the smallest amount of faith can do wonders. The emphasis of Christian living is therefore on simple obedience because of faith, not disobedience until increased faith. Of all the things Jesus requires of us to obey, the command “forgive as I forgave you” is perhaps the most difficult. That is why true Christians need not seek more faith, but need simply work out the faith already given them.

BOOK TIP: For more on what Biblical forgiveness between one another looks like, I highly recommend the booklet me Joel James entitled Forgiving Like God Forgives (free PDF here)


Final Thoughts

“Faith like a mustard seed” in both cases referred to something the disciples already had. Therefore, the application for us is not difficult. “Faith like a mustard seed” is not a manipulative ploy for miracle-makers to excuse their inabilities to heal and to demote those with “a lack of faith”. “Faith like a mustard seed” is a profound motivation for all Christians to do what God commands us simply because our faith is in God. Because we are those of faith, we already have all we need to obey – even the most streneous of ministry duties or most difficult of personal relationship graces.