It’s is very common in this society of ours, to see non-muslims fast during the month of Ramadan, either to seek personal favours from the creator, or in solidarity with friends and or family members. Some also believed that their prayers are specifically answered in the month of Ramadan. This slogan “We worship the same “GOD”, who ever witnesses a festive period should participate in it” is very common among non-muslims and some lukewarm Muslims who participate in and encourage this act.
# A non Muslim once asked Sheik Muhammed Salih Al-munajjid that “When is the month of Ramadan and can someone like me fast properly? What time of the day am I supposed to fast?”
He replied saying;
The fact that you have concern with the blessed month of Ramadan, are questioning its arrival, and anticipating it, is very wonderful. It indicates that you are affected by this great Islamic worship, which consists of abstaining from food and drink, and sexual intercourse from fajr (the break of dawn), until maghrib (the sunset) during the day of the noble month of Ramadan.
As far as its appointed time, my dear respected questioner, the laws of worship in Islam are scheduled according to proof which is clearly traceable and detectable. The evidence which is seen is not estimated. This entails the sighting of the moon, which indicates that the month of Ramadan has begun. So, if we see the new moon, or it is established that someone amongst us has seen the new moon, then it becomes obligatory on the entire Muslim community to fast every day of this month, until we see the new moon for the following month of Shawwal and know that therefore Ramadan has come to an end.
In order for your fast to be accepted, you must first enter Islam by testifying to Allah’s Oneness and believing in the Prophet and following the laws of Islam. We would be happy to see you living a happy life with strong faith, and good years to come, spending them inspired by Islam. We ask Allah to protect you and guide you along.” End quote. Islamqa.info/en/756
On this note, the fast of a non Muslim will only be accepted and rewarded, if an “ex” is added to the “non-muslim”. Thus becoming a Muslim, by accepting Allah as the one true God and believe in the messenger hood of prophet Muhammad (PBUH). Fasting that is deprived of this belief is Null and more like a weight loss exercise. And Allah knows best.
# One of the characteristics of Allah, is Ar-Rahman ( The Beneficent). He distribute wealth, health and other worldly benefits just the way He wills.
Having more of these blessings of Allah does not necessarily mean it’s the effect of answered prayers or high level spirituality. There are a lot of people who doesn’t even believe God exist not to talk of praying to HIM, yet they are massively blessed beyond imagination and so many theist who pray fervently and are still as poor as church rats. So, the worldly gains are not measure of spirituality and acceptance of compulsory deeds such as Solah, Zakah, Ramadan e.t.c and that is why we (Muslims) still always pray that our deeds are accepted from us.
# As for worshipping the same God, please read THE SAME GOD (ALLAH AND YAHWEH)