"Guardian angels exist to protect every human life from its beginning to end." - Pope Benedict XVI
We are never alone, and while our angels always behold the Face of God - they are in the Divine Presence and experience the beatific vision - they are with us continually.
Even unbelievers and those living in sin have a guardian angel who love them:
We may say it is the common teaching of Church commentators that every human being has a guardian spirit in so far as he is human, and not precisely as a result of baptism and a state of grace. St. Jerome therefore says that this angelic custody begins at birth. “What great dignity,” he exclaims, “belongs to souls that each has an angel delegated to watch over it from the moment of its birth” - Fr. HardonPrayers to our Guardian Angel...
“Angel of God, you love God so deeply because you understand God’s love so completely. Ask our Lord to give me something of your great love for God, a repentant sinner, that I may join you in heavenly glory. Our Lord promised that ‘There will be joy among the angels of God over one sinner who repents.’ May I give you and your fellow angels something of this joy over my own generous repentance for my sins.”
“My guardian angel, you always behold the Holy Trinity. You are deeply loved by the divine Majesty. You know how desperately I need the grace of God to know what He wants me to do and the strength I need to surrender my stubborn will to His divine will. How I need your powerful intercession with the Almighty. I trust you will hear my prayer and I am confident that with your help I will live my life as a sacrifice of myself to God and thus merit to join you in that celestial glory where you are waiting for me. Amen.” - Fr. Hardon