Things would barely change. You'd still have thieves, rapists, murders, psychopaths, criminals, racists, misogynists, homophobes, elitists, assholes, etc. Terrorism would remain relatively the same as well according to facts, not sensationalized media propaganda.
An FBI report shows that only a small percentage of terrorist attacks carried out on U.S. soil between 1980 and 2005 were perpetrated by Muslims (6%). See [this] graph for more information.
Organized religion emerged as a means of providing social and economic stability through the following ways:
The states born out of the Neolithic revolution, such as those of Ancient Egypt and Mesopotamia, were theocracies with chiefs, kings and emperors playing dual roles of political and spiritual leaders.[15] Anthropologists have found that virtually all state societies and chiefdoms from around the world have been found to justify political power through divine authority. This suggests that political authority co-opts collective religious belief to bolster itself.[15]
To add to that, it was organized religion that ascended the impoverished mindset of man from the level of a biological animal surviving in the wilderness to a higher-purpose, that had people build beyond their means; the Stonehenge, Aztec temples, Pyramids of Egypt, Shinto temples, etc.
Between 1901 and 2000, 65.4% of all Nobel Prize Laureates were Christians. Christians have won 65.3% of all Nobel prizes in physics. That aside, this long list of Christian scientists includes;
Francis Bacon (1561–1626); Father of empiricism, established the scientific method
Johannes Kepler (1571–1630): Kepler's laws of planetary motion
Blaise Pascal (1623–1662): Pascal's law
Robert Boyle (1627–1691): Boyle's law
Gottfried Leibniz (1646–1716): Polymath who invented Calculus independently of Isaac Newton
Isaac Newton (1643–1727): He is regarded as one of the greatest scientists and mathematicians in history
"Atheism is so senseless & odious to mankind that it never had many professors."
Michael Faraday (1791–1867): He is known for his contributions in establishing electromagnetic theory and his work in chemistry such as establishing electrolysis
James Clerk Maxwell (1831–1879): He is known for his contributions in establishing electromagnetic theory (Maxwell's Equations) and work on the chemical kinetic theory of gases
Lord Kelvin (1824–1907): He won the Copley Medal, the Royal Medal, and was important in Thermodynamics
"With regard to the origin of life, science...positively affirms creative power."
"....the atheistic idea is so non-sensical that I cannot put it into words."
Lord Rayleigh (1842–1919): English physicist who, with William Ramsay, discovered argon, an achievement for which he earned the Nobel Prize for Physics in 1904. He also discovered the phenomenon now called Rayleigh scattering, explaining why the sky is blue, and predicted the existence of the surface waves now known as Rayleigh waves
Arthur Eddington (1882–1944): He is famous for his work regarding the theory of relativity. The Eddington limit, the natural limit to the luminosity of stars, or the radiation generated by accretion onto a compact object, is named in his honor
Max Planck (1858–1947): He won the 1918 Nobel Prize in Physics and is considered the founder of Quantum mechanics
"As a man who has devoted his whole life to the most clear headed science, to the study of matter, I can tell you as a result of my research about atoms this much: There is no matter as such. All matter originates and exists only by virtue of a force which brings the particle of an atom to vibration and holds this most minute solar system of the atom together. We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter."
Georges Lemaître (1894–1966): Roman Catholic priest who was first to propose the Big Bang theory
Werner Heisenberg (1901–1976): German theoretical physicist who made significant contributions to quantum mechanics, nuclear physics and quantum field theory
Kurt Gödel (1906–1978): An Austrian mathematician, logician, and philosopher, Godel is known for what are called Gödel's incompleteness theorems, Gödel's completeness theorem, among other things
The fallacious counter-argument that "religion was prominent and forced on people at the time" is easily dismissed considering Voltaire and Hume were both popular atheists and/or skeptics of religion during the 17-18th century. Furthermore:
The French Revolution of 1789 catapulted atheistic thought into political notability in some Western countries, and opened the way for the nineteenth century movements of Rationalism, Freethought, and Liberalism. Born in 1792, Romantic poet Percy Bysshe Shelley, a child of the Age of Enlightenment, was expelled from England's Oxford University in 1811 for submitting to the Dean an anonymous pamphlet that he wrote entitled, The Necessity of Atheism. This pamphlet is considered by scholars as the first atheistic ideas published in the English language. An early atheistic influence in Germany was The Essence of Christianity by Ludwig Feuerbach (1804–1872). He influenced other German nineteenth century atheistic thinkers like Karl Marx, Max Stirner, Arthur Schopenhauer (1788–1860), and Friedrich Nietzsche (1844–1900).
http://en.wikipedia.org/wiki/History_of_atheism#Nineteenth_century
In conclusion:
Christian presuppositions allowed science to develop. Science was built on the presupposition that God was rational. Because the universe was created by this rational God, “Christian Philosophers linked rationality with the empirical, inductive method” (Schmidt, 218). These philosophers included such giants as William of Ockham (1285-1347) and Francis Bacon (1561-1626). Lynn White states that “From the thirteenth century onward to the eighteenth, every major scientist, in effect, explained his motivations in religious terms” (Quoted in Schmidt, 222). But it wasn’t just the motivations that were explained in religious terms. Too often it is the case that people argue, fallaciously, that they were only Christian because of the time these scientists were born into. They were too afraid, it is alleged, to state their true beliefs. Not only is this utterly without evidence, but it could not be farther from the truth. Many of these scientists spent as much time on theology as they did on science. They credited God with their discoveries. They believed that God had set the universe up in such a way as to be explored by His people.
http://jwwartick.com/2010/04/05/science-thanks-christianity/