The presence of similarities with other religions does not invalidate Islam. As Muslims, we believe that everyone shares the same fitrah (inner nature) that guides us to what is right, so it is natural that many people will share common views, for instance, universal ethical principles. Also, human beings in general suffer from the same challenges, such as anger and greed, so most religions have ways of dealing with these things. We also benefit from similar spiritual practices such as fasting. We are all also dealing with the same spiritual realities, so it is natural that people across cultures will share similar views about spiritual realities. The Qur'an also says that Allah sent prophets too all peoples, to there should be some similarities. In general, the exterior of most religions differs, but the more spiritual or mystical part tends to be similar (for instance, a sense of love, cosmic unity, compassion ,and so forth).