Concise Bible Dictionary:
Besides the common use of this word in many connections, it is used in a special sense to carry the mind back into—
1. Eternity, when the Word was with God, and was God, by whom all things were made (John 1:1-31In the beginning was the Word, and the Word was with God, and the Word was God. 2The same was in the beginning with God. 3All things were made by him; and without him was not any thing made that was made. (John 1:1‑3); Acts 15:1818Known unto God are all his works from the beginning of the world. (Acts 15:18)) (which should read “from eternity”). Also to the eternity of Jehovah, “the beginning and the end” (Rev. 1:88I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty. (Revelation 1:8); Rev. 21:66And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely. (Revelation 21:6); Rev. 22:1313I am Alpha and Omega, the beginning and the end, the first and the last. (Revelation 22:13)).
2. The creation, whether it was creating out of nothing or forming the heavens and the earth (Isa. 64:44For since the beginning of the world men have not heard, nor perceived by the ear, neither hath the eye seen, O God, beside thee, what he hath prepared for him that waiteth for him. (Isaiah 64:4); Heb. 1:1010And, Thou, Lord, in the beginning hast laid the foundation of the earth; and the heavens are the works of thine hands: (Hebrews 1:10)). Also the creation of man and woman (Matt. 19:4, 84And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female, (Matthew 19:4)
8He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so. (Matthew 19:8); Mark 10:66But from the beginning of the creation God made them male and female. (Mark 10:6)).
3. The beginning of Christianity (John 15:2727And ye also shall bear witness, because ye have been with me from the beginning. (John 15:27); John 16:44But these things have I told you, that when the time shall come, ye may remember that I told you of them. And these things I said not unto you at the beginning, because I was with you. (John 16:4); 1 John 1:11That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; (1 John 1:1); 1 John 3:1111For this is the message that ye heard from the beginning, that we should love one another. (1 John 3:11); 2 John 1:5-65And now I beseech thee, lady, not as though I wrote a new commandment unto thee, but that which we had from the beginning, that we love one another. 6And this is love, that we walk after his commandments. This is the commandment, That, as ye have heard from the beginning, ye should walk in it. (2 John 5‑6)).