All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
We have already clarified that Islam is the true religion in the following Fataawa 86091, 16595, 86091, 88906, 173389, 9263, so please refer to them for details on this issue.
If your friends are Christian, then we have stated in previous Fataawa that Christianity has been altered and that the different versions of the Bible contradict each other, so please refer to these Fataawa 8210, 10326 and 90449.
We would like to draw your attention to the following matters:
1) In order for one to debate with those who are upon falsehood, a Muslim should be well versed in religious knowledge lest he doubts his faith or become negatively impacted by the doubts they cast.
2) Avoid being in the company of non-Muslims and be keen on befriending righteous Muslims so that they would help you perform acts of virtue and obedience.
Allah knows best.