The answer to this question is based on the assumption that kissing is in the context of a relationship that is purposely leading to marriage. This is because kissing is an expression of affection, so I do not believe that you should just kiss someone you are just getting to know or someone you do not see yourself getting married to.
HOW CAN KISSING BE WRONG?
So to answer the question - Is kissing wrong? Yes! Kissing can be wrong but it really depends on the intention of the people involved. The bible makes a lot of references to lust - anyone who looks at a woman lustfully, has already committed adultery with her in his heart (Matthew 5:28). This verse shows that you do not need to carry out the action but the thought alone is a sin on its own (i.e. adultery is a sin). So if the reason behind a person deciding to kiss in a relationship is based on fulfilling a lustful desire or the person lusts while kissing, then it is wrong and would be considered a sin. It does not matter if it did not end up with sex because like we see in the bible verse, the thought itself is considered a sin.
Another way kissing can be wrong is if it leads to sin. Kissing can be seen as foreplay, if you watch most movies, it starts with a long intense kiss and then it leads to more. That is why people make the decision not to kiss till marriage. Again let us look at scripture, the bible says if your eyes cause you to stumble (lust), pluck it out and throw it away (Matthew 5:29). This doesn’t mean you should literally pluck your eye out and throw it away lol but it means that you should cut off whatever causes you to stumble or lust. If you know, after reflection and prayer, that kissing your boyfriend/ girlfriend would lead you to doing more and you still decide to do it, then this is also wrong. Remember, it is sin to know what you ought to do and then not do it (James 4:17).
SO KISSING IS NOT ENTIRELY WRONG?
Kissing might not always be wrong. There are different degrees in kissing, for example, a peck would most likely not lead to any lustful thought. Also some people say that their reason behind kissing is not lustful and it is purely an act of affection. In this case, kissing is not wrong. However, it is very important to always have boundaries. Regardless of how strong a person might be, only when they are put in certain situations can they really test their strength. Sexual immorality is not to be toyed with and there is no point testing your limit, instead you should set boundaries to avoid falling into sin! Some things you should think of or ask yourself when setting boundaries are: ‘Should we not kiss when we are alone?’ ‘Should we only kiss after we are engaged?’ ‘Should we only kiss once in a while?’
These boundaries are very important but the most important above all is to pray about it. God is concerned with every detail of your life, so there is nothing you cannot pray about. You should pray about your decision to kiss and the boundaries you should set.
Kissing is not a sin in itself; however, it can lead to sin either through your thought (lust), the degree of kiss and through it leading to more (sexual immorality). This is why as an individual, you need to be completely honest with yourself and ask yourself what the true reason behind wanting to kiss is. There is nothing worth going against God’s word for and if you are going to be with the person forever then the decision not to kiss at all should not be a problem. I hope the points below will help you make the best decision for yourself.
Abstain all together – If you know that kissing will definitely lead to doing more, abstain all together. Remember it is better to cut off your right hand if it will cause you to stumble or lust.
Do not cause another believer to stumble – So let’s stop condemning each other. Decide instead to live in such a way that you will not cause another believer to stumble and fall (Roman 14:13). A relationship takes two, it means dying to yourself and serving another. Your partner might battle with sexual immorality, maybe because of past experiences. Thus, he/she might want to stay away from anything that would lead to sexual immorality and this might include kissing. It is important to respect that decision. This is why you should have a discussion about your boundaries before you get into a relationship because you kissing might secretly make the other stumble or awaken sexual thoughts.
Who is the standard? It is very easy for us to conform to the standards of the world and because kissing is expected in a relationship, we think we have to follow that standard. However, we need to remember that Christ is the standard. If you are convicted to kiss only after marriage, then you do not need to do otherwise so you do not look 'weird' or seem 'extra'.
I pray that this post has helped anyone that needed an answer to this!