Every statement and/or argument must be supported by evidence, and this evidence should be provided.
Without evidence, a statement could be called opinion and your confidence that the statement is true is related to your opinion of the person making the statement.
Furthermore, the fundamentals of the statement may change over time (due to a change in technology, performance, environment, implementation, etc) making the statement's supporting arguments and statements invalid, and therefore invalidating the claimed statement of truth.
Without the original evidence, you will not allow the reader to determine whether the statement is still applicable. This evidence should be sufficiently verbose for a reader, at the same time to reproduce and come to the same conclusion.