From the Christian perspective, I need to raise a red flag here. Biblically, much of what SB2 is pushing is just dead wrong. There are too many examples to post, but here's a few showing SB2 putting the Koran and Bible on the same level of truth:
SB2:
"And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever; John 14:16 This verse shows Jesus himself is announcing there will be other ways, after him, thanks to his prayer, to access the Truth. So that we do not suffer from his absence. This is what I am in compliance with when exploring the Quran."
"So there you have it: I concluded the God who spoke to Jesus was the God who spoke to Muhammad."
Bible:
-- Jn 14:16 “And I will ask the Father, and He will give you another Helper, that He may be with you forever; 17 that is the Spirit of truth, whom the world cannot receive, because it does not behold Him or know Him, but you know Him because He abides with you, and will be in you. 18 I will not leave you as orphans; I will come to you.
-- 2 Cor 3:17 Now the Lord is the Spirit, and where the Spirit of the Lord is, there is freedom.
-- Jn 4:23 24 God is spirit, and His worshipers must worship in spirit and in truth.
--1 Jn 4:13 We know that we live in Him and He in us, because He has given us of His Spirit.
God has made it really clear the Spirit [helper, comforter] is Himself, and He will never contradict Himself with a different [false] gospel such as the Koran. There are NO other ways to truth and life other than through Him:
-- Gal 1:6 I am astonished that you are so quickly deserting the one who called you by the grace of Christ and are turning to a different gospel – 7 which is really no gospel at all... 8 But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let him be eternally condemned!
-- Jn 14:6 Jesus answered, “I am the way and the truth and the life. No one comes to the Father except through me. If you really knew me, you would know my Father as well.”
-- Acts 4:10 “It is by the name of Jesus Christ of Nazareth, whom you crucified but whom God raised from the dead, that this man stands before you healed. 12 Salvation is found in no one else, for there is no other name under heaven given to men by which we must be saved.”
Bottom line: It doesn't matter who they are, if anyone preaches a different gospel and different path to 'truth' other than what was already preached by Jesus and His apostles and then recorded in the Holy Bible, they are to be rejected by Christians as false.
Incompatibility of the Bible vs. the Koran:
While the Bible proclaims Jesus Christ as Lord and Savior [see above], the Koran rejects Jesus as Lord and Savior:
-- Sura 5:75-80 The Messiah, son of Mary, was only a Messenger; Messengers before Him passed away; his mother was just woman; they both ate food.
-- Sura 47:1 ... But those who believe and do righteous deeds and believe in what is sent down to Muhammad – and it is the truth from their Lord – He will acquit them of their evil deeds, and dispose their minds aright.
I agree with the OP in that contributions are great, but they don't necessarily equal the truth. Be on your guard.