'Unwavering' in the Bible

"I solemnly tell you," said Jesus, "that if you have an unwavering faith, you shall not only perform such a miracle as this of the fig-tree, but that even if you say to this mountain, 'Be thou lifted up and hurled into the sea,' it shall be done;

For we never fail to remember your works of faith and labours of love and your persistent and unwavering hope in our Lord Jesus Christ in the presence of our God and Father;