Galileo could not prove his theory. The problem wasn’t that the Church was against it, it was that Galileo was trying to pass off an unproven theory as a fact. It would take until the 1800s until the theory was made a law by secular science. Look this up by simple google-ing, development of heliocentrism.
number 2, it directly contradicts the Bible,
Judges 5:31 … but let them that love him be as the sun when he goeth forth in his might…
The Earth is stable:
1 Chronicles 16:30 Fear before him, all the earth: the world also shall be stable, that it be not moved.
The Sky is a solid thing, spread over the Earth
Job 37:18 Hast thou with him spread out the sky, which is strong, and as a molten looking glass?
The Earth is on a foundation and doesn’t move:
Hebrews 1:10 And, Thou, Lord, in the beginning hast laid the foundation of the earth; and the heavens are the works of thine hands:
Suggestive of a flat Earth:
Revelation 1:7 Behold, he cometh with clouds; and every eye shall see him
The Church was not willing to disregard the Bible for a hypothesis.
Catholics weren’t the only ones who did not agree with Galileo. Protestants rejected his works as well. However the Church’s condemnation of Galileo is often exaggerated.
Quoted from Wikipedia: (use the links given on the site if you wish for actual info)
The decree of 1616
The Letter to the Grand Duchess Christina prompted the papal authorities to decide whether heliocentrism was acceptable. Galileo was summoned to Rome to defend his position. The Church accepted the use of heliocentrism as a calculating device, but opposed it as a literal description of the solar system. Cardinal Robert Bellarmine himself considered that Galileo’s model made “excellent good sense” on the ground of mathematical simplicity; that is, as a hypothesis (see above). And he said:
“If there were a real proof that the Sun is in the center of the universe, that the Earth is in the third sphere, and that the Sun does not go round the Earth but the Earth round the Sun, then we should have to proceed with great circumspection in explaining passages of Scripture which appear to teach the contrary, and we should rather have to say that we did not understand them than declare an opinion false which has been proved to be true. But I do not think there is any such proof since none has been shown to me.”
—Koestler (1959), p. 447–448
Bellarmine supported a ban on the teaching of the idea as anything but hypothesis. In 1616 he delivered to Galileo the papal command not to “hold or defend” the heliocentric idea. The Vatican files suggest that Galileo was forbidden to teach heliocentrism in any way whatsoever, but whether this ban was known to Galileo is a matter of dispute.