We understand that you're struggling to say no and to stand up for yourself. First, let's remember what the Word of God says in Matthew 5:37 WEB, But let your 'Yes' be 'Yes' and your 'No' be 'No.' Whatever is more than these is of the evil one. It is important to be firm and clear in our decisions, and to stand by them.
In Ephesians 4:27 WEB, we're warned not to give place to the devil. Often, our inability to say no stems from fear—fear of disappointing others, fear of conflict, or fear of missing out. However, when we allow these fears to control us, we're giving place to the devil.
It's also crucial to remember that our battle is not against flesh and blood, but against the rulers, against the authorities, against the world rulers of this darkness, against the spiritual forces of wickedness in the heavenly places. Therefore, take up the whole armor of God, that you may be able to withstand in the evil day, and, having done all, to stand. Stand therefore, having the utility belt of truth buckled around your waist, and having put on the breastplate of righteousness, and having fitted your feet with the preparation of the Good News of peace, besides all these, taking up the shield of faith, with which you will be able to quench all the fiery darts of the evil one. And take the helmet of salvation, and the sword of the Spirit, which is the word of God; with every prayer and request, praying at all times in the Spirit, and being watchful to this end in all perseverance and requests for all the saints (Ephesians 6:12-18 WEB).
We need to be strong in the Lord and in the power of His might. We need to put on the whole armor of God so that we can stand against the wiles of the devil.
Let's pray together:
Dear Heavenly Father, we come before You in the name of Jesus Christ, lifting up our brother/sister who is struggling to say no. We pray that You will give them the strength and courage to stand firm in their decisions, and to not give place to the devil. Help them to put on the whole armor of God, to stand against the wiles of the devil, and to be strong in You and in the power of Your might. We rebuke the spirit of fear and timidity, and we release a spirit of boldness, courage, and love. In Jesus' name, we pray. Amen.
Remember, God has not given us a spirit of fear, but of power, love, and self-control (2 Timothy 1:7 WEB). It is only by the name of Jesus Christ that we have access to God and by which we can be saved (John 14:6, Acts 4:12). Stand firm in your faith and in the power of His might. Be encouraged to read the Bible and be prepared to share the Good News of Jesus Christ. Do not be selfish and enticed by the offer of the things of the world.