THESE two verses follow on and are derived in their meaning from the previous verses. Taken on their own, or as another statement attached on to the first, it will miss the depth and importance of what Jesus has already said.
Jesus now says “whoever welcomes a little child like this in my name welcomes me. But if anyone causes one of these little one who believe on me to sin, it would be better for him to have a large millstone hung around his neck and to be drowned in the depth of the sea”. The literal translation of verse 6a reads “and whoever offends one of these little ones who believe in me ....”. The word translated 'offend' or in the NIV translated as 'sin' is 'scandalizo' which has the meaning of 'to put a snare' or 'a stumbling block' or in this chapter 'to cause to stumble'.
If we see this as an independent statement, or simply as another teaching on how to treat children, we will soon turn away from it as being of little relevance to ourselves. To be loving and caring of children, and to love them as Christ loved little children, is something which is axiomatic to our thinking. Any who claim or aspire to be disciples of Jesus will never seek to harm children, but always be seeking their well-being, and their safety. They will want to love them. In the past when the attitude to children was that they should be seen and not heard, peoples' attitude to children often tended to be unkind and unloving, but things have changed in our time, and generally speaking children are seen as important and to be loved.
Jesus speaks of a 'child like this'. He is not simply speaking of another child, but also of one who is childlike as Jesus has been commending. A 'child like this' is everyone who has taken the teaching of Jesus in verses 1 to 4 to heart, and has become humble before Jesus, and in trust and dependence is ready to be humble and accept only what Jesus wants for them, even if this may be some insignificant place in the church and society.
Such an attitude is not excluding anyone from very responsible situations in the service of Christ. Paul showed this childlike humility and dependence on Christ. We have only to read Philippians 3 to see this. Paul did not think himself important but rather as the chief of sinners. It was because he was so humble that he could be used by God in such a great way.
However because of the pride and sinfulness of the human heart even amongst Christians, those who are childlike in this way are often despised in the church, looked down upon, and marginalized. This treatment does not necessarily cause such a Christian to sin, but it does make their Christian life very difficult and cause them to stumble, with doubts, fears, sense of uselessness, and so on. Under such pressure a person can find their faith being eroded, and can find themselves tempted to give up, and even lose their faith altogether. I believe this is what Jesus is speaking about here. It is true that if by our actions and example we put temptation of any kind in the way of another believer, and so cause them to sin we are doing a seriously evil action. However it seems to me that the meaning Jesus is placing before us here is of causing another humble believer to stumble in their Christian life in some way because we treat them carelessly, unlovingly or by looking down on them and marginalizing them. Great harm can be done to another believer through such treatment. This is why Jesus speaks so strongly against such behavior here.
There is another aspect of causing to stumble that is very real. Our behavior is an example to other believers. Being strong we may be able to do things which are no temptation to us, but if another believer follows our example, because of their weakness, it may lead them into temptation which causes them to fall into sin. This is what Paul warns against when he speaks of considering the weaker believer before we follow a course of action. In Corinth this was concerning food offered to idols. The strong believer knows that the idol is nothing and so eating food offered to them means nothing. The weaker believer is very fearful of the supposed power of the idol, and if led to eat food offered to idols could then be caused to stumble.
The fact is that such behavior is not uncommon in church fellowships and so the teaching of Jesus here is so very much needed.
We need to take to heart the severe censure which Jesus pronounces against such treatment of another believer. Jesus tells us that such behavior is so condemned and hated by God, that it would have been better if a person who acts like this had never been born. Christ loves his childlike disciples as he loves little children, and anyone who acts in a hateful way towards them is doing such a very wicked thing that they are placing themselves in danger of worse than being drowned for ever in the sea. They are acting like the devil.
The fact is that Jesus loves his childlike disciples, as he loves little children, and any who receive them with love and affirm them are in fact receiving Jesus, and pleasing him. If we love the sheep of the sheepfold, we are loving the shepherd, and receiving the shepherd – that is, doing this to and for the shepherd.