My question comes from Hebrews 1:14Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?
See All.... It says Angels are God spirits sent to protect Christians. I do not have problem with this scripture. My problem is, do we still have Angels TODAY doing this work? If yes, how do we identify them as not to grief them and what forms are they?

The Bible does teach of angels that minister to those who are the heirs of salvation. In speaking of children, Jesus referred to "their angels" (Matthew 18:10Take heed that ye despise not one of these little ones; for I say unto you, That in heaven their angels do always behold the face of my Father which is in heaven.
See All...). Evidently, we have angels who have the special job of looking out for us.

However, there is no command or even need for us to identify them or know what forms they take. In fact, as long as they are in spirit form, we will not see them. It took a miraculous opening of the eyes for the young man with Elisha to see the horses and chariots of fire around them (2Kings 6:17And Elisha prayed, and said, LORD, I pray thee, open his eyes, that he may see. And the LORD opened the eyes of the young man; and he saw: and, behold, the mountain was full of horses and chariots of fire round about Elisha.
See All...). We are to focus on pleasing God, not His created beings (Proverbs 16:7When a man's ways please the LORD, he maketh even his enemies to be at peace with him.
See All...; Colossians 1:10That ye might walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God;
See All...; 1Thessalonians 4:1Furthermore then we beseech you, brethren, and exhort you by the Lord Jesus, that as ye have received of us how ye ought to walk and to please God, so ye would abound more and more.
See All...; 2Timothy 2:4No man that warreth entangleth himself with the affairs of this life; that he may please him who hath chosen him to be a soldier.
See All...). 

On those occasions when angels do make themselves visible to men, they look like any other men. The angels that appeared to Abraham when he was in his tent door looked like three men (Genesis 18:1-2 [1] And the LORD appeared unto him in the plains of Mamre: and he sat in the tent door in the heat of the day; [2] And he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground,
See All...). We find this throughout scripture. When the book of Hebrews refers to the possibility of entertaining angels, it says we would do it "unawares" (Hebrews 13:2Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.
See All...). In other words, if you did meet an angel, you would not be able to distinguish him from any other man. 

The bottom line is that we are told about the angels to encourage us. God has His created beings watching over us and caring for us. However, we are not supposed to be looking for them in any special way and we are not supposed to do special things to please them. They minister to us so that we may give ourselves to the Lord and serve Him.