Christians always try to conflate the servitude of one Israelite to another and the enforced slavery of non-Israelites.
When they do that they are either revealing that they haven't read the bible or they are lying for Jesus.
The god of the OT approved of slavery of the very worst kind. Foreign slaves were the personal possessions of Israelites. They were inherited like any other chattel and the owner had the right to beat them to death 'for they are your possession'.
The god of the OT also approved of taking virgins as sex slaves on an industrial scale.
It would take any xtian 2 minutes to find the references and read them objectively. When we combine these facts with the way christians identify Jesus with the god of the OT we are left with the conclusion that 'gentle Jesus meek and mild' prescribed slavery, kidnap and rape.
Edited to add - I just read that link posted by Sea Breeze. The way it treats the biblical data on foreign slaves makes the 'overlapping generation' doctrine sound reasonable.