NET
19 To do this you must hold firmly to faith and a good conscience, which some have rejected and so have suffered shipwreck in regard to the faith.
Darby
19 maintaining faith and a good conscience; which [last] some, having put away, have made shipwreck as to faith;
KJV
19 Holding faith, and a good conscience; which some having put away concerning faith have made shipwreck: