1 Jn 5:11-13, Rev 3:20
The Old Testament proverb says that he who finds wisdom finds life. (Proverbs 8:34-35)
Proverbs 8:34 Blessed is the man that heareth me, watching daily at my gates, waiting at the posts of my doors. 35 For whoso findeth me findeth life, and shall obtain favour of the Lord.
Those who believe in Jesus as the Christ have eternal life. (1 John 5:11-13)
1 John 5:11 And this is the record, that God hath given to us eternal life, and this life is in his Son. 12 He that hath the Son hath life; and he that hath not the Son of God hath not life. 13 These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
Now Jesus is knocking on the door of people's hearts. Those who accept Jesus as the Christ have life. (Rev 3:20, John 1:12)
Rev 3:20 Behold, I stand at the door, and knock: if any man hear my voice, and open the door, I will come in to him, and will sup with him, and he with me.
John 1:12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: