The most important thing is for a couple to be one - that is, united. When the two of you are one, it will be difficult for a third party to negatively affect you. If you are open to each other and do not keep secrets from one another, when one partner hears something strange, the tendency will be to share it immediately with your spouse. If you have that culture in your relationship, it will be easy to nip any strange influence in the bud, but if you have the culture of keeping everything secret, you stand the chance of the devil wreaking a lot of havoc in your home, long before you realize it, by which time, things might have gotten out of hand.

You cannot totally cut off in-laws because of their close relationship with your spouse, but when you have a good relationship with your wife, a closeness that cannot be easily destroyed; it will be difficult for anybody to come in. You will discover any strange influence upon your wife as soon as it comes and you will begin to ask the necessary questions immediately.

Sometimes influences are so subtle you don't even know you are being influenced, but when you are close to your spouse, he or she will easily spot it.

Once you notice such influences, go to work. The first thing to do is to draw her attention to the changes in her life. Secondly, deliberately create situations where your wife's involvement with them is reduced and checked. If for example, she has a routine of hanging out with her folks at specific times, say weekends, you could find something more interesting that both of you will be involved in at that particular period, so as to cut her away from that influence for a while. After some time, she will get used to the new arrangement and the wrong influence will be removed.