The Bible does not name cosplay
Cosplay is a modern hobby, so Scripture does not give a rule about dressing as a fictional character or attending a convention. That does not leave Christians without guidance. Paul tells believers to do everything for God's glory, including ordinary choices around food, drink, and daily life (1 Corinthians 10:31).
Creativity, costume-making, performance, friendship, and enjoying stories can be good gifts. Yet a hobby is not automatically wise simply because it is fun. The question is not only, “Am I allowed?” It is also, “Can I take part in this thankfully and honour God while doing it?”
Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God.
Consider the character and costume
Some characters and stories centre on things Christians have good reason to avoid, such as cruelty, sexual immorality, occult power, or celebrating evil. A costume is not necessarily an endorsement of every part of a fictional world, but it is still worth asking what you are choosing to portray and why.
Modesty matters too. Christians may differ on particular clothing choices, but Scripture calls believers to think about what is honourable and pure (Philippians 4:8). If a costume is designed to attract sexual attention, stirs lust in you or others, or leaves you feeling uneasy before God, that is a meaningful warning sign.
Listen to your conscience
Paul addresses believers who faced disputed choices and says that acting against faith is sin (Romans 14:23). In other words, do not pressure yourself into cosplay because friends are doing it, and do not dismiss a genuine unease simply because others feel free to participate.
Pray honestly. Could you thank God for this hobby? Does it leave room for worship, relationships, generosity, and responsibilities? A pastime can become unhealthy when it consumes money, time, attention, or identity in a way that belongs to God. Christians are called to live under Christ's lordship, not be mastered by anything (1 Corinthians 6:12).
And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.
Love people, not just your freedom
Your choices affect other people. Paul urges Christians not to use their freedom carelessly where it may become a stumbling block to someone else (1 Corinthians 8:9). That does not mean living in fear of every opinion. It means showing thoughtful love, especially when a costume or event could confuse, tempt, or distress people close to you.
So a Christian may enjoy cosplay with discernment. Choose characters and clothing you can wear with integrity, set sensible limits, and be willing to walk away from anything that pulls your heart from Christ. Read the passages in context, talk with mature believers who know you well, and let your decisions grow from faith rather than pressure.