Another except from Spiritual Mindedness by John Owen.
Remember your former spiritual state. Remember how it was when you first became a Christian. Remember how strong and vigorous your spiritual hunger and thirst, how greatly you desired Christ and his grace and mercy. Now compare it to your present spiritual state. This will help you to arouse your desires to return to God and to be healed of your present low spiritual condition (Hos 2:7).
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Call to mind the former days. Consider whether those days where better than now, when in your lying down and your rising up, you had many thoughts of God, and how sweet and precious they were to your souls; when you rejoiced at the remembrance of His holiness; when you had zeal for His glory, delight in His worship, and were glad when they said 'Let us go to the house of God together'; when you poured out your souls in prayer and experienced his love reviving your hearts. Remember what peace of mind, and what joy you had, and compare it to what you have got now in your present lukewarm state.