In my opinion, the wearing of makeup is not a sin. The apostle Paul did mention about the over indulgence or too much focus on the external things eg braiding of the hair or perhaps even makeup or type of jewellery worn. The point he was making is that our focus should be on developing our relationship with GOD Almighty. And not focusing exclusively on just our physical appearance alone. Jesus did say Man ( or woman) can not live on bread alone (or material or physical things) and the rest we all know. Moderation is the key. Women need to look good. It's a personal decision. We must not be dogmativ or fanatical about it. May we all see the need to love and encourage each other instead of rivalry and hatred. Have a wonderful day!