Are there guardian angels? This verse suggests they have a role to play in the lives of people who are "close to salvation." Much of the book of Hebrews speaks to those who have heard about Christ but seem to be hesitating about committing themselves fully to trust Him as Savior. Angels may protect these vulnerable people from Satan's attacks. Thank the Lord, if you have trusted Him as your Savior, that He made sure you would have the opportunity to hear the Gospel and you were protected until you turned your heart over to the Lord.
Note also Psalm 91:11 - "For He shall give His angels charge over you, to keep you in all your ways." Though this may be true of the angels ministry to Jesus, Matthew 4:11, it is also written for all believers. God does give His angels a responsibility to watch over us, even after we're saved. Note their ministry to Daniel and his three friends recorded in Daniel 3 and again in chapter 6.
Also see Matthew 18:10 - "Take heed that you do not despise one of these little ones, for I say to you that in heaven their angels always see the face of My Father which is in heaven." These children are being watched over and cared for by God's angels and these angels report to God whenever they observe someone offending any child.
Don't live carelessly just because you have a guardian angel. Angels have been used by God to inflict pain on wayward people, and that can include Christians too!
Thank God for the ministry of angels to all believers, and that includes you.