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.