Richard Sibbes, in The Soul’s Conflict, examines the causes of spiritual discouragement that are internal to ourselves (i.e. those that are not directly attributable to some external cause, such as God or Satan).

1. Lack of knowedge and understanding.  ‘Ignorance, being darkness, is full of false fears. In the night time men think every bush a thief.’

2. Forgetfulness.  See Heb 12:5.  ‘We have no more present actual comfort than we have remembrance…He that hath formerly known things, takes ready acquaintance of them again, as old friends; things are not strange to him.’

3. Not valuing our comforts, Job 15:11.

4. Focusing too much on what we do not have, rather than on what we do have.

5. False reasoning.  Lack of feeling does not necessarily mean lack of faith.  Sins may be exaggerated, as well as minimised.  That we are not great Christians does not mean that we are not Christians at all.

6. Proceeding by a false method and order in judging our spiritual state. ‘They will begin with election, which is the highest step of the ladder; whereas they should begin from a work of grace wrought within their hearts, from God’s calling them by his Spirit, and their answer to his call, and so raise themselves upwards to know their election by their answer to God’s calling. ‘Give all diligence,’ saith Peter, ‘to make your calling and election sure,’ 2 Pet 1:10, your election by your calling. God descends down unto us from election to calling, and so to sanctification; we must ascend to him, beginning where he ends. Otherwise it is as great folly as in removing of a pile of wood, to begin at the lowest first, and so, besides the needless trouble, to be in danger to have the rest to fall upon our heads.’

7. Looking too much to our santification, and not to our justification.  See Phil 3:8f.  It is Christ’s righteousness, and not our own, ‘wherewith being decked, we please our husband, and wherein we get the blessing.’

8. Neglecting to keep a clear conscience.  ‘Where there is not a pure conscience, there is not a pacified conscience.’

9. Ignorance of our Christian liberty, by unnecessary scruples and doubts.  True, Christian liberty may be abused.  But it can also be neglected.

10. Idleness.  ‘An unemployed life is a burden to itself.’

11. Omission of the duties and offices of love.  Let us not reach the end of life, looking back with regret over missed opportunities to do good!

12. Lack of resolve.  Some limp along, turning this way and that, making slow and painful progress.  See James 1:6.  ‘God will not speak peace to a staggering spirit that hath always its religion and its way to choose. Uncertain men are always unquiet men.’