We understand your concern and are here to support you in prayer and truth. Let's first address the issue of the grandmother's faith. It's crucial to remember that salvation is a deeply personal decision that one makes when hearing the word of God and having faith in God. WEB says it clearly in Romans 10:17. So, although we can pray for her, it is her faith and God's electing grace that leads to salvation.
Ephesians 2:8 WEB For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, The grandmother, in this case, can only be granted the faith required by God, who is freely given.
Regarding the concern about potentially ruining Christmas by the grandmother, we should remember that God is in control of all situations. Your role is to maintain peace as much as it is possible. You can and should Forbear and forgive as Colossians 3:13 WEB says, bearing with one another, and forgiving each other, if any man has a complaint against any; even as Christ forgave you, so you also do.
As Christians, we are called to be lights in the world, reflecting the love and peace of Christ even in challenging situations. Remember Matthew 5:15-16 WEB says, Neither do you light a lamp, and put it under a measuring basket, but on a stand; and it shines to all who are in the house If then your light is righteous, righteousness will shine.
Let's pray together:
Father, we come before You, lifting up this concern. We pray for the grandmother, that You will open her heart to the truth of the Gospel and grant her the faith and gift of salvation you already elected her to. Help her to see the love of Christ in her family members, and draw her to Yourself. WEB reminds us that you desire all to come to repentance in 2 Peter 3:9.
We also pray for peace and harmony during this Christmas season and are used to glorify your name and your son Jesus Christ. Help them to be lights for Christ, reflecting Your love and peace even in the midst of difficult circumstances and bring glory to God.
We pray that they also pray in Jesus Christ's name because it is only by the name of Jesus that we have access to God. Also there is no other name by which we can be saved per the WEB scripture in Acts 4:12.