This sounds like God exists !

Counter: The amount of energy in the universe is always constant as per Law of Conservation of Energy.

Favour: But the observable universe is an open system. An open system can exchange both energy and matter. Thus there can be reduction in energy. So can we say God exists as far as observable universe is concerned?

Transfer of Energy is possible in Closed system too though not possible in Isolated System

The law of conservation of energy and law of conservation of information are applicable to a system only if it is isolated. The entire universe, meaning everything there is, including things we cannot see, is an isolated system because it has no "surroundings"; it's literally everything there is. Obviously, a system cannot exchange energy or matter with "surroundings" that do not exist. But if there are no surroundings then to what the Universe is expanding?  

Counter: Space is being created as it is expanding.
Nasadiya Suktam, RV 10.129 implies the same that space is created when it says "नास॑दासी॒न्नो सदा॑सीत्त॒दानी॒म् नासी॒द्रजो॒ नो व्यो॑मा प॒रो यत्।" - Neither existence nor nonexistence was there Neither matter nor space around

Favour: Then how can the system be isolated or closed? Where is the creation of space happening?

Counter: May be there are multi-verses. It may still be closed.

Favour: But not Isolated. and Closed system can transfer energy. 

Conclusion: If Universe is an open system or a closed system then it can lose energy. Thus there can be a decrease in energy. The conscious being causing order out of disorder by spending energy is a possible analogy. This analogy is not applicable in isolated system but universe cannot be an isolated system since it is expanding and new space is created. 

Thus with the second law of thermodynamics it may be concluded a conscious being causes order in the universe.

      

Spacetime explained in Nasadiya Sukta of Rig Veda before Einstein's General Relativity Theory

ति॒र॒श्चीनो॒ वित॑तो र॒श्मिरे॑षाम॒धः स्वि॑दा॒सी ३ दु॒परि॑ स्विदासी ३ त्।
 रे॒तो॒धा आ॑सन्महि॒मान॑ आसन्त्स्व॒धा आ॒वस्ता॒त्प्रय॑तिः प॒रस्ता॑त्॥५॥

Reins of the link, a grid of crisscross lines,
Holds all the seeds and mighty forces, Microcosmic forces within And macro forces out above. (5) Rig Veda 10th Mandala, 129th Hymn

Now imagine the two-dimensional projection of a three-dimensional analogy of spacetime curvature described in general relativity.

Spacetime: space and time should be considered together and in relation to each other - grid of crisscross lines, holding all the seeds and mighty forces - Gravity, EM, Strong and Weak Forces, (Dark Matter & Dark Energy ?).

Does that ring a bell?

Banglar paatraani Mamata
Tomar ki asheem Khamota
Bhashche desh jolche Janata
Ghashphule eki Kata
Shamle nao ei Maarongatha
Bhulona purboshurir katha
Manush jokhon korbe bichaar
Thakbe na aar voter Chhata