Revelation 1:5 And from Jesus Christ, who is the faithful witness, and the first begotten of the dead, and the prince of the kings of the earth. Unto him that loved us, and washed us from our sins in his own blood,
What is a faithful witness? Faithful means "strict or thorough in the performance of duty, true to one's word, steady in allegiance, loyal, constant, reliable, trusted." A witness is "a person who has seen or can give first-hand evidence of some event, a person or thing giving or serving as evidence, a person who testifies, esp in a court of law, to events or facts within his own knowledge." Proverbs 14:5 says, "A faithful witness will not lie..."
Jesus is Faithful to the Father's will
Matthew 26:39 And he went a little further, and fell on his face, and prayed, saying, O my Father, if it be possible, let this cup pass from me: nevertheless not as I will, but as thou wilt.
John 5:30 I can of mine own self do nothing: as I hear, I judge: and my judgment is just; because I seek not mine own will, but the will of the Father which hath sent me.
Jesus is Faithful to perform what he says, to keep what He promised
1 Thessalonians 5:24 Faithful is he that calleth you, who also will do it.
2 Thessalonians 3:3 But the Lord is faithful, who shall stablish you, and keep you from evil.
2 Timothy 2:13 if we believe not, yet he abideth faithful: he cannot deny himself.
Hebrews 10:23 Let us hold fast the profession of our faith without wavering; (for he is faithful that promised;)
Jesus is Faithful over His House
Hebrews 3:2 who was faithful to him that appointed him, as also Moses was faithful in all his house.
Hebrews 3:5-6 5 And Moses verily was faithful in all his house, as a servant, for a testimony of those things which were to be spoken after; 6 but Christ as a son over his own house; whose house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end.
Jesus is a Faithful High Priest
Hebrews 2:17 Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people.
Jesus is Faithful to Forgive
1 John 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
Jesus was Faithful unto Death
Philippians 2:8 and being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross.
We ought to be Faithful
Rev 2:10 Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life.