I know if they still live next to me in the
future, our children are around the same age. I do not want to cause problems in my marriage and have problems with the neighbors, plus I
do not want to be self righteous.

You might have another concern as a Christian. That would be for the souls of these two very nice people who are living next door to you. 1 Corinthians 6:9-10, 18-20 (NIV): "9 Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders 10 nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God. … 18 Flee from sexual immorality. All other sins a man commits are outside his body, but he who sins sexually sins against his own body. 19 Do you not know that your body is a temple of the Holy Spirit, who is in you, whom you have received from God? You are not your own; 20 you were bought at a price. Therefore honor God with your body."

Romans 1:26-27 (NIV): "26 Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones. 27 In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion."

As a Christian you will be concerned for all people. As you have opportunity you will want to witness to them about the love of God in Christ Jesus for them. First you may want to hear from them, if you already have not heard from them, that they are, in fact, lesbians, and that it is not just neighborhood talk. Then talk with them about your own sin and your forgiveness in Jesus. Especially talk with them about Jesus and his love for them. They have had their children baptized. That is wonderful! Talk with them about what the Bible says about homosexuality. The two passages quoted above will be helpful. Talk to your pastor about this and get advice from him regarding your conversations with them. Tell them that you do not want your conversation to get in the way of your friendship. Then, after the conversation, regardless of their reaction, be a good, kind, and generous Christian neighbor to them.

God’s Blessings!