The Amplified Bible says, "Never lag in zeal and in earnest endeavor; be aglow and burning with the Spirit, serving the Lord."  Other translations give the idea of being diligent in what you do and showing great emotion, warmth, passion or enthusiasm.

God wouldn’t tell you to do something He hasn’t equipped you to do.  If He says to be full of zeal and diligence, and to be aglow and burning with the Spirit, then He has equipped you to do just that!  This is something that has to come from the heart and can't be faked.  To have passion like this then you will need to live true to what's in your heart.  God has put a burning desire within you and as you identify it and go with it then you will have this kind of fervency strengthening you.

Confession: