Koinoneo: that is, they are in that condition, as their common lot.
'In like manner' is strictly 'near to,' as Phil. 2.27, 'close to.'
There is an intended difference here between the words for 'partake' (koinoneo) and 'took part in' (metecho), ver. 14. The first, referring to the children, is a common equal sharing of the nature. The second, referring to Christ, means, he took a part in it; and refers always to something outside myself, but which I take, or take a part in. The first work refers to a joint participation in that which belongs to me or to known fellowship. The second is used in ch. 5.13, 'partakes of milk,' in 1Cor. 9.10, where the reaper gets a share in the sower's hope, and in 1Cor. 10.17,21,30, 'partake,' where 'partaking' (metecho) is proof of participation in fellowship (koinonia), ver. 16. The word does not say how far the taking share went.
Or 'who had;' lit. 'having,' without reference to time. Cf. ch. 13.20.