We are transformed by the promises God gives to us but not by our committment or promises we give to God.
God always keeps His promises : Let God be true and every man a liar. (Romans 3:4). Our effort to keep our promises to Him always proved futile, and in the long run, we end up forgetting our promises or going back to our old ways (... we are liars!). Remember your new year resolutions - do you ever keep them?
Just believe and rest in His promises, not your promises,.. then you will not be shortchanged or frustrated.