Are Amitabha and Sakyamuni the same?

As to Theravada there can be only one Buddha,Because Buddha is the name for the one who alone without any help or learning understand all of Buddhism and then go on to teach it to others.The question here is not between two Buddhas but between two versions of Buddhism.in Theravada there is no mentioning about a buddha called amithbha,as to Theravada there is Sakyamuni Buddha who is the teacher of the current buddhism and there were many before him in this "Kalpa (Era)"

There are 2 truths in Buddhism. Conventional truth which is the truth happening everyday around us and keep on changing every moment. Absolute truth which is the truth that goes beyond space and time and always be true. Sakyamuni Buddha and Amitabha Buddha are the same in Absolute truth but different in conventional truth. And neither the same or difference in Absolute truth. Both answer are correct and incorrect depend on which truth are you looking at. Both Buddhas are interbeing means they're coexist. I'll explain why. Buddha has 4 references:
1) Sakyamuni Buddha, prince Siddhartha who has achieved enlightenment and taught the four noble truth.
2) All being who has achieved enlightenment (unlimited buddha).
3) Buddha nature, an awareness of our infinite potential (unlimited buddha)
4) Emptiness, collective consciousness, reality as it is of the universe. (unlimited buddha).
A Buddha would be all 3. Amitabha Buddha means Infinite light reality. Lights gave life to the earth. Earth gave birth to human. Queen Maya gave birth to Siddhartha prince and he became buddha. Without light there is no Sakya Buddha. Sakya Buddha is also the light, is also Amitabha. Sakyamuni Buddha is the light of wisdom, the earth, the sky, the rain, and all conditions, everything in the universe that made up of who he is (this concept is Karma). This is Interbeing. So everything is Buddha. Unlimited Infinite Buddha in all directions. Sakyamuni Buddha taught us the Dharma so that we can be awaken, transform our suffering into happiness and realize the reality to become "ONE" with all Buddha in the past, present, and future in all directions in the cosmos. Anyone could come up with countless stories about any Buddha in the Cosmos, but non is matter because the Buddha is within each of us that is waiting to be discover. No one can walk the path but ourselves. Once we have truely found ourselves, we'll be connected to all and made possible in this lifetime. Nirvana. Some says "The Kingdom of God" . Spending a lifetime looking for the Buddha outside and not recognizing the Buddha inside is meaningless.

In my view Amitabha Buddha is nothing but an addition by later monks to support the veda, mantras and brahmanic philosophy to spoil the core, logical and reasonable teachings of Gautam Buddha. If someone thinks I am wrong please give the reference where does Gautam Buddha talks about Amitabha Buddha, it will be great help to me in search of truth.

You are right that God is not the supreme being in Buddhism. That belongs to the Buddhas, and your original nature.

There is no self, no substance, and no beginning to ignorance.

Are Amitabha and Sakyamuni the same? Since this question is not very specific, there are a few ways to answer. (1) Sakyamuni and Amitabha took different paths to become a Buddha. Sakyamuni was Siddhartha Gautama before he was enlightened. Amitabha was Dharmakara before he became enlightened. So from this perspective they are different. (2) Some say that Sakyamuni was an emanation of Amitabha. I am not sure how this works, perhaps Amitabha was the source of Siddhartha's enlightenment? Sakyamuni was called the light of the world. But, this would mean that they are the same. (3) At the level of suchness, all Buddhas are one and the same. Same reason that our tathagatagarba is identical with Amitabha. So, Sakyamuni is also the same as Amitabha.

No, the Buddhas do not reside over galaxies, but over pure lands. Amitabha resides over Sukhavati, while Sakyamuni has his pure land on Vulture Peak. Vaipulya sutras (Lotus, Golden Light, etc.) explain that while the ordinary person sees different buddhas, there is actually just one. This goes back to the Buddhist concept of anatman and the realization that we are our thoughts only. Also, because of the concept of interdependent origination, we could say that these pure lands are all interpenetrating, or that there is only one pure land.

As for Theravada, Our Gautama Buddha had never mentioned about Amitabha. At the time being, he became a buddha under bodhi tree, he looked up the whold universe finding who he should pay homage or who is better than himself in terms of sila, samadhi and prajna, but unfortunately he couldn't have found one. It means he's the only enlightened one and no one in the whole universe is in higher rank than him. And there are 3 buddhas before him in this world. There will be another in future. So in total, There are 5 buddhas in this world. There was a life time, he vowed for the buddhahood in front of one buddha. And from that world till this current world, there're only 28 buddhas before him. If asked for the exact world, that would be a lot like there are 140 zeros behind 4 + 100000. That was the world he passed thru to fill up PARAMI to become buddha in our world's 4th budhha.

As mentioned before, there are different levels of meaning. The confusion comes from assuming that they are contradictory or exclusive instead of complementary and inclusive. That is, the reality of Amitabha (Đức Phật A Di Đà) and that all appearances are mind only are not opposing views.

In fact, they perfectly support each other. For those who naturally incline for viewing Amitabha as a real entity, they are gradually introduced to the teaching of emptiness, if they are open for it in this life. For those who prefer everything as empty, they definitely have to understand that there is no emptiness besides dependent origination, and the Pure Land path is real and effective exactly because reality is mind made.

An important difference is that while relying solely on buddha-remembrance leads to birth in the Pure Land, failing to see that there is no emptiness besides appearances leads only to some higher heavens at best, or to lower realms if one also denies the functioning of karma.

Source: Astus

Amitabh and Buddha are not the same. Amitabh is the infinite light of revelations , source of innumerable miracles. Buddha discourages display of any miracles.

From my understanding Gautama Buddha and Amida Buddha are two different Buddha. When Amida made his vows it was immeasurable kalpas ago and He just became Buddha 10 kalpas ago. In the Infinite Life Sutra Sakyamuni Buddha hints that his reason for being born and become Buddha in this life was to announce Amida's great vows so all sentient beings can benefit. Also all Buddhas in the 10 direction also praise Amida Buddha and teaches the Amitabha Sutras. Eventually all beings from 10 direction would be vow to be born to Amida Buddha's Pureland where condition is perfect for cultivating wisdom and merit that you'll fast track to Enlightenment within 3-5 kalpas instead of immeasurable kalpas. Sakyamuni Buddha said that the Infinite Life Sutra is very difficult for sentient being to believe, but I hope everyone would read it, develop a Bodhi Mind, gain faith in Sakyamuni's teaching and Amitabha's vows, take vow to be born to Amitabha's Pureland, recite His name until their last breath. Namo Amitabha!

As far as I know, being a Buddha is not about being a Supreme Being, it is about being enlightened. It is a state of knowledge and detachment achievable by anyone (in theory). Also remember that each school of Buddhism has it's own interpretation of the enlightenment, how to achieve it and of how many Buddhas there are.

Amitabha is a Mahayana concept which needs to rely on another Mahayana framework called Trikaya. With this framework, the historical Sakyamuni Buddha is considered to be the "Nirmanakaya" (created body) while Amitabha Buddha is considered to be the "Sambhogakaya" (reward-body) of the Trikaya.

Interesting! So does mahayana buddhism have a considerably different view of the nature of the buddha than theravada (which most SE Buddhists appear to follow)?

It's not the case that Mahayana has a considerably different view from Theravada. Most ideas are traceable back to the original teaching. If you look at a tree, over time it's obvious that it'd grow new branches. While the new branches can't be said to be exactly the same as one another but they all share the same root and trunk.