The Greek word for Paradise is paradeisos, which means “a royal park” or “a garden.” It is a New Testament term only, and it is found in three passages.
The first is Luke 23:43, where Jesus said to the crucified thief: “Today, you will be with me in Paradise.”
The second passage is 2 Corinthians 12:4, which states that the apostle Paul was caught up into Paradise.
The third passage is Revelation 2:7, which speaks of the future: the tree of life will be in the Paradise of God.
Paradise describes the abode of the righteous ones, no matter where that abode may be at any point in time. In Luke 23:43, it is the same as Abraham’s bosom (Luke 16:22) because, at that point, all the righteous ones went down to the righteous side of Hades, known as Abraham’s bosom. Until the death of Jesus, Paradise was in Abraham’s bosom.
According to 2 Corinthians 12:4, Paradise today is in Heaven. At the Ascension of Jesus, Abraham’s bosom was emptied. Believers no longer descend down to Abraham’s bosom but now go directly into Heaven. Today the believer’s abode is Heaven, and so Paradise is now in Heaven.
Revelation 2:7, speaks of the future when Paradise will be in the New Jerusalem, which means that the abode of Paradise will change again. As the New Jerusalem on the new Earth will be the abode of all believers after the 1000-year Messianic Kingdom, even so, Paradise is going to be in the New Jerusalem.
To summarise, from Adam until the Ascension of Jesus, Paradise was in Abraham’s bosom. From the Ascension of the Messiah until the end of the Messianic Kingdom, Paradise is in Heaven. Then after the Millennial Kingdom and for all eternity, Paradise will be in the New Jerusalem on the new Earth.