Ephesians 5:11 And have no fellowship with the unfruitful works of darkness, but rather expose them.It seems that the lady John is addressing has a love for people that pours out of her; however, John is warning her to use discernment. She (and us) need to discern who we receive and whom we fellowship with; especially those actively preaching and teaching doctrines of demons. After all, if a doctrine, religion or philosophy is not from God it is a doctrine of demons.
1Timothy 4:1 Now the Spirit expressly says that in latter times some will depart from the faith, giving heed to deceiving spirits and doctrines of demons,It seems that this lady’s heart was “in the right place” as we like to say; however, just because our intentions may seem to be from a pure heart does not excuse us from filtering our conduct through the Word of God. If God’s Word says (and it does) that we are not to be unequally yoked, in other words, we are not to fellowship with, receive in to our house, or be involved in ministry with false religions, then we shouldn’t.
2Corinthians 6:14-18 Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness? 15 And what accord has Christ with Belial? Or what part has a believer with an unbeliever? 16 And what agreement has the temple of God with idols? For you are the temple of the living God. As God has said: "I WILL DWELL IN THEM AND WALK AMONG THEM. I WILL BE THEIR GOD, AND THEY SHALL BE MY PEOPLE." 17 Therefore "COME OUT FROM AMONG THEM AND BE SEPARATE, SAYS THE LORD. DO NOT TOUCH WHAT IS UNCLEAN, AND I WILL RECEIVE YOU." 18 "I WILL BE A FATHER TO YOU, AND YOU SHALL BE MY SONS AND DAUGHTERS, SAYS THE LORD ALMIGHTY."
2John 1:9-11 Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and the Son. 10 If anyone comes to you and does not bring this doctrine, do not receive him into your house nor greet him; 11 for he who greets him shares in his evil deeds.
The very clear take away from 2John is that (just as John warns us in 1John 4) we need to test every spirit, we are NOT to receive false teachers, and the intent of our heart along with the deception of false teachers can cost us dearly.
2John 1:7-8 For many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist. 8 Look to yourselves, that we do not lose those things we worked for, but that we may receive a full reward.
Ephesians 6:10-12 Finally, my brethren, be strong in the Lord and in the power of His might. 11 Put on the whole armor of God, that you may be able to stand against the wiles of the devil. 12 For we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age, against spiritual hosts of wickedness in the heavenly places.