'Stedfastly' in the Bible

Then again he laid his hands upon his eyes; and he looked stedfastly, and was restored, and saw all things clearly.

In solemn truth I tell you that if any one shall say to this mountain, 'Remove, and hurl thyself into the sea,' and has no doubt about it in his heart, but stedfastly believes that what he says will happen, it shall be granted him.