Zeal, true zeal, comes from the Father above and enables a man of God to do the work of God and persevere.
Zeal is that quality that infuses true delight in doing a task much like little children delighting in what they do.
Ambition is not zeal.
Zeal is of the Spirit and ambition is of the flesh.
Ambition is born of a selfish desire to advance oneself and is an attribute of the most wicked men of all generations.
Zeal and ambition are in opposition to each other.
Zeal results in a meek and gentle behavior while ambition results in a proud and aggressive behavior.
To those who have become lukewarm in their Christian walk, Jesus said "Be zealous therefore and repent."
Unless you be as little children you can in no way be a part of the work of the Kingdom of Heaven.
Ask God to restore your zeal and He will.