Well, let's put that to the test.
Galatians 1:8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
Now, if scripture is not the only source for what the apostles taught please show another source where the apostles taught the assumption of Mary.
Galatians 1:8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
Now, if scripture is not the only source for what the apostles taught please show another source where the apostles taught the assumption of Mary.
Perhaps you missed the part where it says "we have preached unto you," not "contained in Scripture." It is the church that preaches. No where in the Bible does it state that it is the only source of truth.
Amen