In the gospel to Theophilus, Luke collects eyewitness accounts, facts, and evidence of many pivotal events in the early church when he was a co-worker of the apostle Paul. During his travels, he is likely to have encountered many key figures who played a key role in Jesus' earthly ministry. It is for this reason that Luke is confident that his work will prove useful. This is of significant benefit to modern readers as well.
Throughout history, the enemy has employed a wide range of strategies to undermine the truth of God's Word. Numerous false writings, teachings, witnesses, and facts flooded into the fledgling church in these early years. Therefore, Luke states in his narrative to Theophilus that he has carefully researched everything concerning the life of the Lord Jesus Christ.
The gospel of Luke contains good tidings of salvation for all, a message of great joy. It is critical that we remain alert and sober. Like a roaring lion, the enemy seeks to dismantle the gospel of Christ and undermine our faith. Nevertheless, we should hold fast to that which we have, knowing that the Lord Jesus is the way, the truth, and the life. He has forgiven us of our sins and granted us life everlasting for His glory and honor.

Dear Heavenly Father, Your guidance has sustained us throughout our lives, and You will continue to guide us into the future if we stay on Your path. Thank you for blessing us with the good news of the gospel and for saving us through faith in Jesus Christ. Thank You for Your Word and the wonderful grace that is extended to all who put their faith in Christ for salvation. May Christ keep me strong in the evil days, knowing that soon He will return to take us to be with Him. 
In Jesus's name I pray. Amen.