The Jehova witness asked me,where Jenah is found?-He is saying, it is this earth. For ur info. I know that, the question is dealt in shura Ibrahim ch.14 and shura Zumer ch.39 of the holly Quran- please answer me to be a in better position to answer him-may Allah bless you

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Paradise that Allaah promised for His believing slaves is in the heavens as confirmed in the Book of Allaah and in the Sunnah of the Prophet . Allaah Says (what means): {And in the heaven is your provision and whatever you are promised.}[Quran 51:22]

Ibn ‘Abbaas interpreted {whatever you are promised} to mean Paradise. Moreover, Allaah informed us in chapter 53 that Paradise is at the Lote Tree of the Utmost Boundary. Allaah Says (what means): {At the Lote Tree of the Utmost Boundary. Near it is the Garden of Refuge [i.e. Paradise]}[Quran 53:14-15]

The Garden of Refuge is above the seventh heaven as confirmed in authentic Prophetic narrations reported by Al-Bukhari and Muslim . Moreover, the Prophet informed us that the roof of Al-Firdaws (the highest rank in Paradise) is The Throne of Allaah, and The Throne is above the seventh heaven. 

Anas ibn Maalik was asked about the location of Paradise whether it is in the heaven or on this earth and he responded: “Which heaven or earth could encompass Paradise?” He was asked: “Where is it then?” He answered: “It is above the seven heavens underneath The Throne.” Indeed, there are many texts proving this.

Allaah did not mention that Paradise is on the earth, neither in chapter 14 [Ibraaheem] nor in chapter 39 [Az-Zumar]. It might be that you are referring to Paradise from which Aadam [Adam] was taken out. Some scholars are of the view that it was not Paradise that Allaah has prepared for the believers on the Day of Judgment, but rather another Paradise which may be in any part on this huge universe. 

We believe that the Christian who told you that Paradise is on this earth said so because he does not believe in the Last Day.

Jehovah Witnesses do not believe in the Hereafter and in the reward or punishment therein; neither do they believe in Paradise or Hellfire. 

Therefore, we advise you not to debate with that Jehovah Witness unless you have enough religious knowledge to call him to Islam and refute his misconceptions.

As regards calling him to Islam, you may benefit from Fataawa 81979, 88906 and 88051.

Allaah Knows best.