Why is it important to determine these things? Put it this way, destroying the culprit of losing intimacy with God is the most effective way to reclaim back your passion for Him.
Sure, there are times we lose the drive of spending time with the Lord, but like the relationship He wants with us, it is always a two-way street. We take part as God's people.
If the fire is fading out, are you able to supply the wood?