Just wondering if the Bible mentions anything about Christians and Believers that own or actually wear “Religious Pendants, Medallions, Amulets, Necklaces, Crosses, Jewelry, etc?” Does the Bible even mention or say if wearing these kinds of symbols or anything will “increase your chances” of bringing yourself good luck or “protecting you from evil”?? I was thinking about buying like an Irish Cross necklace or something: But I’m not 100% if I would want to buy it if the Bible would probably not condone me having one?
So far as I know, the Bible doesn't say anything specifically about it. Jesus did disparage conspicuous displays of religiosity. Matthew 23:5. The Bible also condemns superstition, e.g., the ignorant faith that an object, even a religious one, has magical powers. Colossians 2:8. If you think the object itself will bring you good luck or ward off evil, you might reconsider. There might also be a problem if you're wearing these because you're unduly attached to material baubles. (Luke 12:15; 1 John 2:16-17; Matthew 6: 26-34) But if it's a Christian symbol and you're just wearing it as a reminder of our faith in God, I see no problem.
I'd compare wearing a cross on a cord or chain to having a bible with gold lettering or a cross or dove embossed/engraved on the cover. Adornment is not wrong, but immodesty of appearance and idolatry (worshiping that image object) are. There are many verses in the OT and NT that point to my brief summary here. If you purchased a Celtic cross in gold, wore it for a time, and it no longer serves a useful purpose on your salvation journey, then you can easily sell gold jewelry and give the money to a charitable cause. Unless and until it becomes a problem for you, one of immodesty or idolatry, enjoy it as a reminder of your faith. The same goes for one received as a gift - if it isn't consistent with the path you seek to follow, remove it from your life, but find a charitable use for its value. Remember, you wear a cross under your clothing, so it is largely unknown and unseen, except to you and to God. Similarly, you may have a Bible with a gold cross and gold lettering on a black leather cover, but you don't go waving it around. When you read your Bible, only you and your God know that it has a visually striking book cover.