Teresa Of Ávila said this quote

Let nothing disturb you,Let nothing frighten you,All things are passing away:God never changes.Patience obtains all things.Whoever has God lacks nothing;God alone suffices.

~ Teresa Of Ávila

But, as I know that strength arising from obedience has a way of simplifying things which seem impossible, my will very gladly resolves to attempt this task although the prospect seems to cause my physical nature great distress; for the Lord has not given me strength enough to enable me to wrestle continually both with sickness and with occupations of many kinds without feeling a great physical strain. May He Who has helped me by doing other and more difficult things for me help also in this: in His mercy I put my trust.

~ Teresa Of Ávila

The closer one approaches to God, the simpler one becomes.

~ Teresa Of Ávila

In order that love be fully satisfied, It is necessary that It lower Itself and that It lower Itself to nothingness and transform this nothingness into fire.

~ Teresa Of Ávila