Now, brothers and sisters, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand. (NIV)

AND NOW let me remind you [since it seems to have escaped you], brethren, of the Gospel (the glad tidings of salvation) which I proclaimed to you, which you welcomed and accepted and upon which your faith rests (AMP)

Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; (KJV)