No, they're not equal
Yes, they are equal
Science is always more accurate then religion.
'Why' and 'how' are not equal in concept, in scope. 'Why' is much farther reaching than 'how' is. 'Why' is much more complex than 'how' is.
As @FreedomBeforeEquality said, "how?" and "why?" are completely different questions. Science can certainly answer "why?", but it'll be a secular answer, and the problem with that is all secular answers to "why?" go further and further down the cause-and-effect chain until they reach the end, and that is where only religion, philosophy and pure speculation can provide answers. Asking "how?" is just explaining the series of events, asking "why?" is asking what was at the beginning of that series of events, which is far more difficult and far reaching than anyone can prove without a shadow of doubt. I hate to say I agree with @FreedomBeforeEquality, but "why?" is a lot harder than "how?"
Religion seems to answer less than science. Philosophy probably gives a better impression of "Why" but nothing for "Why" is certain. "How" we can be pretty certain about.
Religion would give you "instructions" for a life on a daily basis (i.e. to be holy, just, etc..); whereas Science would explain to you why we live life on a daily basis. i.e. Biology, chemistry, physics.. etc.. Two different things. It is oft that one would contradict the other based on what religion you are in: it is not hard to understand if we would take Religion as a Pastor and Science as an Atheist. Why? Because science itself would falsify the existence of God (as it has so done with deliberately trying to prove the Big Bang theory).
"How" can determine the "why."
The question 'why' persists because we, as humans, have historically been accustomed to things happening for intelligible reasons. The question, however, does not apply to the Universe beyond intelligent effect.
Science explains how natural processes work, and religion explains what science can't, such as the origin of the universe and the creation of life. Science says that the Big Bang created the universe, and religion explains the only probable cause: a supernatural being. However, they must work together. Science without religion leads to the conclusion that everything is impossible, because it shows how nothing has an absolute origin, meaning that nothing exists, which is contradictory to the obvious fact of existence. Religion without science leads to ignorance, because people will just assume that God directly affects everything without actually investigating natural processes.