For Da'wah (inviting to Islam) theres three main points you talk about; I believe:


1) Allaah

2) Prophets

3) Afterlife




1) In Allaah. You believe in Allaah's Lordship, none is worthy of worship except Him, and you can discuss His 99 names and attributes mentioned in the Qur'an [speech of Allah] and Authentic Sunnah [prophetic ways/sayings]

Allaah is the Lord of all the worlds, and no-one else except Him created everything, including ourselves. Even the beauty that you got. He created us simply so we would obey Him over the creation. Why do we obey Him? So we can be just/kind to the creation and be rewarded with good for that. Allaah was always, and will never die, no-one created Him and He created everything.


The laws of man are always so the person gets the best for themselves, so a ruler/leader might only make some rules which will be for his/her benefit, but why obey this person when you should be following the laws of your own Creator? Doesn't your Creator have more of a right over you? This is why we obey Him, and if Allah can make us live in this world, its easy for Him to bring us to life back once again. And why should Allah create us if we have no purpose in life? This is why we live our lives according to how God wants us to live, in return for reward [for obeying Him and submitting to Him] or turning away and rejecting Him, and therefore being punished for turning away from all the blessings which He has blessed you with.



Note: If you study the lives of the Prophets of God, you'll see that they lived simple lives because they don't have a desire to cheat people or trick them for money or power, but instead - they simply call to God and try to enjoin good and push away evil.