The Guardian Angel always accompanies us as our principal witness. It is he who, at your particular judgement, will remember the kind deeds you performed for Our Lord throughout your life. Furthermore, when you feel lost, before the terrible accusations of the enemy, your Angel will present those intimate desires of your heart — which perhaps you yourself might have forgotten — those proofs of love which you might have had for God the Father, God the Son, God the Holy Spirit.
That is why you must never forget your Guardian Angel, and that Prince of Heaven shall not abandon you now, or at that decisive moment.
--Josemaria Escriva, Furrow, 693