Some Christians often think about the time when Jesus Christ will return to earth to judge the living and the dead. However, world renowned evangelist Billy Graham said Christians should spend time not on wondering when the Second Coming will be, but preparing for it instead.

In a question-and-answer column, Graham was asked by an anonymous person if a so-called "spiritual guru" from his city claiming that "he is divine" can possibly be the Second Coming of Jesus.

Graham replied, saying the "spiritual guru" is definitely not Jesus, explaining that when Christ returns to earth, it will be apparent to a lot of people.

"I can confidently say that this person is not Jesus — because when Jesus returns, He will come from Heaven with power and glory, and the whole human race will see Him," the evangelist wrote in the column, as quoted by The Christian Post.

He also quoted Matthew 25:31-32, which states that when the Son of Man comes back to earth, "all nations will be gathered before Him."

He further advised Christians to stop worrying or thinking about the Second Coming, noting that no one knows when it is going to happen, except God.

"I do not know, and neither does anyone else. In fact, Jesus warned us against trying to make precise predictions about His coming, or even to claim that we know, although over the centuries some have tried (and failed)," Graham said.

The evangelist likewise enjoined Christians to prepare instead for Jesus' return to earth, which he said is a certainty.

"But I do know this: Someday Christ will come again — and then it will be too late for us to repent and be saved. And even if death comes to us before then, now — not later — is the time to put our faith and trust in Him," Graham said.