How do I know if I'm praying in line with the will of God?

from the old testament

• When Assyria came against Judah, King Hezekiah went into the temple to pray to the Lord: “O Lord our God, save us, please, from his hand, that all the kingdoms of the earth may know that you, O Lord, are God alone” (2 Kings 19:19). Hezekiah’s prayer was in the will of God because it emphasized how saving Judah would glorify God.

from the new testament

• Loving our Enemies: In Matthew 5:44, Jesus says: “But I say to you, Love your enemies and pray for those who persecute you…” Loving our enemies might entail praying for their salvation, praying for God to work healing in their life, or praying for any number of situations they may be going through.
• Forgiveness of others: We should forgive those who we have something against (Mark 11:25). In fact, we can do this during our daily prayers with God (Matthew 6:12).
• Resistance from temptation: In Matthew 26:41, Jesus tells His disciples: “Watch and pray that you may not enter into temptation. The spirit indeed is willing, but the flesh is weak." . Whenever we are faced with temptation, we can pray to the Lord to give us His strength and wisdom to guide us away from temptation and into fulfilling His will.
• Missionary Outreach: In Luke 10:2, Jesus tells His disciples: “...’The harvest is plentiful, but the laborers are few. Therefore pray earnestly to the Lord of the harvest to send out laborers into his harvest.” We can pray in similar ways by asking God to put His hand over the work of missionaries today and to lead more people into missionary outreach.
• Boldness in sharing the Gospel: No matter how safe or severe our situation is when it comes to sharing the Gospel, we can pray to the Lord for boldness (Acts 4:29).
• Salvation of Jews: We can follow Paul’s example in Romans 10:1, and pray for the Jews’ salvation—for them to come to the knowledge and belief in Jesus Christ.
• Ministers of the Word: Leader ministry work is a heavy responsibility. We should pray for those in ministerial leadership such as pastors, teachers, and elders in the church (Colossians 4:3; 2 Thessalonians 3:1; Ephesians 6:18–19).
• Lifting up Thanksgiving: First Thessalonians 5:16–18 says, "Rejoice always, pray without ceasing, give thanks in all circumstances; for this is the will of God in Christ Jesus for you." We know praying and giving thanks are within God's will. (Colossians 4:2; Philippians 4:6–7).
• Government Officials: First Timothy 2:1–4 says: “First of all, then, I urge that supplications, prayers, intercessions, and thanksgivings be made for all people, for kings and all who are in high positions, that we may lead a peaceful and quiet life, godly and dignified in every way. This is good, and it is pleasing in the sight of God our Savior, who desires all people to be saved and to come to the knowledge of the truth.” It may not always be easy to pray for those we don’t agree with politically, but we should anyway. This can mean praying for their salvation as well as asking the Lord to guide them to make wise decisions.
• Getting Wisdom: To follow God's will in prayer, we need wisdom—that is, instruction and guidance from Him. James 1:5–6 says, "If any of you lacks wisdom, let him ask God, who gives generously to all without reproach, and it will be given him. But let him ask in faith, with no doubting, for the one who doubts is like a wave of the sea that is driven and tossed by the wind."
• Healing: If we or if someone else is enduring a physical illness, we should lift prayers up to God about the situation (James 5:13, 5:16); we can ask for healing no matter how small or severe the illness.
• Confessing our sin: First John 1:9 says: “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.” Confessing our sin is relationship maintenance in our walk with God. When we confess our sins to Him, we can trust that He will forgive us no matter what we have done.

implications for today

God’s children can confidently approach Him in prayer: "And this is the confidence that we have toward him, that if we ask anything according to his will, he hears us. And if we know that he hears us in whatever we ask, we know that we have the requests that we have asked of him” (1 John 5:14–15). But how can we know if we're praying in accordance with God's will? The Bible is full of instructions and examples. It is not just the content of what we pray that matters but our motives (James 4:3) and heart posture (Matthew 5:23–24). We are to come humbly and persistently before God, knowing that He will answer our prayers in His way and in His timing. We may not always know what God’s specific will is, but we can rely on Him to do what is right and best. So we must pray in submission to Him, asking for His will to be done (Matthew 6:10): "And we know that for those who love God all things work together for good, for those who are called according to his purpose" (Romans 8:28).