If you've been at some calling for a long time you risk losing the fire.
You're in danger of not just feeling tired, but burning out and no longer caring.
Yet to serve God well, you need to keep the fire alive. And avoid the lukewarmness that leads you to just go through the motions and makes the Lord feel sick (Rev.3:16).
So how do you stoke up your zeal?
By constantly going back to the One who baptizes with the Holy Spirit and with fire.
You can't reignite yourself.
But you can rekindle your love for the people God has put in your life and the mission He has given you by staying close to Him.
"Our God is a consuming fire" (Heb.12:29).