Passage
Your father Abraham rejoiced to see my day: and he saw it, and was glad.
John 8:56 (KJV)
Nearby Context
John 8:54 Jesus answered, If I honour myself, my honour is nothing: it is my Father that honoureth me; of whom ye say, that he is your God:
John 8:55 Yet ye have not known him; but I know him: and if I should say, I know him not, I shall be a liar like unto you: but I know him, and keep his saying.
John 8:56 Your father Abraham rejoiced to see my day: and he saw it, and was glad.
John 8:57 Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham?
John 8:58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.
Study Lenses
The verse centers on "father", "abraham", "rejoiced", and "glad". It is saying that the verse draws attention to "father" and "abraham", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 55's "Yet ye have not known him but..." into verse 57's "Then said the Jews unto him Thou...", so "father" and "abraham" belong inside that flow. In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "father" and "abraham" with trust shaped by these words, not by a vague optimism outside the passage.