Hi there,
It seems like you have a big ordeal to go through. The important thing for you to do is make sure your wife is on the same page as you. Even if she does not agree with you you should still make sure that she trusts your decision and is not going to be angry because of it. I think that you made the right decision to not let them in your home because it is your responsibility to keep your home pure. That does not always mean disallowing unbelievers but it does mean disallowing their practices and if they will inevitably practice and/or promote their practices in your home then you need to put the foot down. I also find it difficult to think of pertinent scriptures however there are those that are at least indirectly related.
"Let love be without dissimulation. Abhor that which is evil; cleave to that which is good. 10 Be kindly affectioned one to another with brotherly love; in honour preferring one another; 11 Not slothful in business; fervent in spirit; serving the Lord; 12 Rejoicing in hope; patient in tribulation; continuing instant in prayer; 13 Distributing to the necessity of saints; given to hospitality. 14 Bless them which persecute you: bless, and curse not. 15 Rejoice with them that do rejoice, and weep with them that weep. 16 Be of the same mind one toward another. Mind not high things, but condescend to men of low estate. Be not wise in your own conceits. 17 Recompense to no man evil for evil. Provide things honest in the sight of all men. 18 If it be possible, as much as lieth in you, live peaceably with all men. 19 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord. 20 Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head. 21 Be not overcome of evil, but overcome evil with good." Romans 12:9-21
"Be not deceived: evil communications (companionship) corrupt good manners." 1st Cor 15:33
"Know ye not that a little leaven leaveneth the whole lump?" 1st Cor 5:6
"Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? 15 And what concord hath Christ with Belial? or what part hath he that believeth with an infidel? 16 And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. 17 Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you, 18 And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty." 2nd Cor 6:14-18
I would also encourage you to be careful with these verses because we are called to be "lovers of hospitality" (Romans 12:13, 1st Tim 3:2, Titus 1:8, 1st Pet 4:9). You are the head of the home (1st Cor 11:13, Eph 5:23, 1st Tim 3:4) and you must do that which you deem to be best for you family.
I recently had my dad living with me (and he is a Christian) and he was staying with us for quite some time. We live in a trailer so there was not much space for myself, my wife, my two kids and my dad so I had to ask him to leave. He lives in a motorhome now and that's too bad but that is what I deemed to be the best for my family. I saw that my time alone with my family was impeached and so I took the hard road with my dad. You relationship with your God is the most important then your wife then your kids then the rest of your family. I hope that what I said here will help you.
In Christ, Randy.