Paul, a bondservant of God and an apostle of Jesus Christ, according to the faith of God's elect and the acknowledgment of the truth which accords with godliness, in hope of eternal life which God, who cannot lie, promised before time began, - Titus 1v1-2
This is a simple little phrase, but what a great promise and great reminder. Its context alone is a blessing. Paul served God based on his hope of eternal life which God had planned before the foundation of the world. The great comfort of that is that the God who did all this cannot lie. His promise is true and valid. My eternal life is not based on my whim and fancy, but on the promises of a God who cannot lie.
That whole truth about God is blessed and comforting. The very fact that God cannot lie means that every promise in His word is trustworthy. His promise of eternal life is true, and so is His promise that He will not forsake us, that He loves us, that He will take care of us, that we can cast all of our cares and concerns on Him, and that He will keep His promises and care for us.
I don’t have to wonder if God will keep His promises. He will, because He cannot lie. His promise of eternal life is not conditioned on anything. Some of His promises are based on our trust, but they all are valid and unchangeable.
God cannot lie. If He says it, it is true. All we have to do is accept it, believe it, and trust it.