International Standard Version because we do not look for things that can be seen but for things that cannot be seen. For things that can be seen are temporary, but things that cannot be seen are eternal.
American Standard Version while we look not at the things which are seen, but at the things which are not seen: for the things which are seen are temporal; but the things which are not seen are eternal.
Young's Literal Translation we not looking to the things seen, but to the things not seen; for the things seen are temporary, but the things not seen are age-during.