There is no argument that scientifically verifies that there exists a God. If it were there, the debate would have ended. The premise of religion is to believe in God rationally, not just scientifically.
Intelligent design is a sufficient argument to prove rationally that can be a God who has created this wonderful systematic knowledgeable world. Then comes Quran in the light of established history which tells that a prophet of God came with the challenge that he would be triumphant despite being apparently helpless and his opponent will perish and it happened the way it was told. Then there is a number of predictions and challenges in the Quran which came true as they are. Then there is the Quran itself which claimed to be protected and it is there protected, every word of it. Then there is Bani Israel, whose fate is living evidence in history and in the present. Their fate is steered by God in accordance with the covenant of God made with them according to which they will be humiliated if they disobey God and will prosper and be triumphant if obeys Him. and that since they denied Jesus, they are declared to be bound to serve under the hegemony of Christians.
These are some major points to ponder upon. The details are provided in our books and talks.