'Joint heirs' in the Bible
And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together.
That they who are of the nations should be joint heirs, and a joint body, and joint partakers of the promise in Christ Jesus through means of the glad-message, -
By faith, he sojourned in the land of promise, as a foreign land, in tents, dwelling, along with Isaac and Jacob, the joint-heirs of the same promise;
Ye husbands, in like manner, dwell with your wives according to knowledge, giving honor unto the woman, as unto the weaker vessel, as being also joint-heirs of the grace of life; to the end that your prayers be not hindered.