Ro 10:1 Brethren, my heart's desire and prayer to God for Israel is that they may be saved.
2 For I bear them witness that they have a zeal for God, but not according to knowledge.
Zeal for God doesn't save a sinner. You can be hot, zealous and on fire in serving the Lord and still remain unsaved. Your service is just filthy rags if it isn't the fruit of salvation.
These Jews, Paul attests, have a zeal for God but they are not saved. Zeal saves no one. Zeal is not the Savior, you should know. Salvation is found in Christ and what He did on the cross.
Yup, you are not saved by YOUR zeal for Him, rather, you are saved by HIS zeal for you when He died on the cross for you. It doesn't mean that we are not to be zealous for God. No, we should. Zeal has its proper place. But we are not to trust in it for our salvation. Rather, we are to trust in the Savior and what He did on the cross in order to be saved.