I’m sorry about your grandmother — that kind of loss is hard, and the pull to feel close to her again makes complete sense. Scripture is direct about this question, though, and it’s worth understanding both what it says and why.

Deuteronomy 18:10-12 lists consulting mediums and those who "call up the dead" among practices God calls detestable, grouped together with other forms of divination. Isaiah 8:19 asks the pointed question directly: "should not a people seek unto their God? for the living to the dead?" — framing the whole practice as looking in the wrong direction entirely. And 1 Samuel 28 records King Saul’s visit to the medium at Endor as an act of unfaithfulness so serious that 1 Chronicles 10:13-14 names it as one of the reasons "the Lord slew him."

Part of why this matters practically connects to what we’ve talked about elsewhere: since "the dead know not any thing" (Ecclesiastes 9:5) and are resting until the resurrection, whatever a medium claims to channel isn’t actually your grandmother’s aware spirit reaching back to you. Scripture describes deceptive spiritual forces capable of counterfeiting exactly this kind of contact (2 Corinthians 11:14 notes that "Satan himself is transformed into an angel of light") — which is precisely why the practice is warned against so strongly rather than simply discouraged as unnecessary.

The comfort Scripture actually offers is different, and I’d say better: your grandmother, if she died in faith, is at rest, safe, and unaware of any time passing — not lost, not distant, not in need of being reached. Paul tells believers to grieve, but "not, even as others which have no hope" (1 Thessalonians 4:13), pointing forward to a real reunion at the resurrection (v. 16-17) rather than a séance in the meantime. That’s a hope worth holding onto instead.