There is no rule saying that donations to a love offering can’t go through the church. The issue is whether the gifts are deductible as charitable contributions for the donor or not.  If the donor gives money for a particular person, like for the pastor, then it is not tax deductible.  This means it is not reported on their contribution statements and they cannot count it as a charitable contribution.  These gifts and love offerings can be done, they just have to be reported properly.