Are you connected to a VPN? Gospel Library has issues installing content while connected to a VPN on Android 6 and up, due to how these versions of Android differentiate between network types. This will be fixed in Gospel Library 5.3.0. Some VPNs also have web filtering, which could potentially block Gospel Library content servers, which adds another factor (some web filtering services, such as T-Mobile's Web Guard, are known to block the Church's content servers). Finally, there's a known issue affecting a subset of devices (Galaxy S5 on Android 6 is one example) where the "Limit Mobile Network Use" setting (if it's on) will prevent installing content even when connected to Wi-Fi. This will also be fixed in Gospel Library 5.3.0.
So, some possible workarounds: 1) Temporarily disable your VPN, if you have one installed, to see if that fixes the problem; 2) Check for any content blockers or web filters installed as apps or as services on your network; and 3) See if you have "Limit Mobile Network Use" turned on.
Samuel Bradshaw • If you desire to serve God, you are called to the work.