A lot of Christians struggle with assurance. Sometimes they have doubts about the truth of the gospel: “I’m not sure God even exists.”

More often, they believe the gospel but aren’t sure it’s good news for them. “Yeah, Jesus died and rose again, but maybe I’m not included.”

This isn’t really a problem of assurance but of re-assurance. We’re like a child after his father scolds him, who needs to know his father still loves him.

The worst way for you to regain assurance is to put your life under a microscope. Inevitably, you’ll find tiny blemishes you didn’t know were there. And then you’ll twist in the wind and swirl down into the void.

When you doubt, don’t stare in a mirror. Instead, remember. Remember God’s promises. Remind yourself your Father adopted you in baptism and feeds you every week at His table.

Remind yourself God gave His Son, and, if He didn’t spare His Son, He will also with Him freely give us all things (Rom 8:32).

Of course, we do need to examine ourselves, to identify and destroy sins. We need to recognize our immaturities and grow out of them.

We need to examine ourselves in faith. That means: examine yourself prayerfully. Ask the Spirit to search your heart and reveal your sins (Psa 19:12; 139:23-24), so you can confess and abandon them.

Ultimately, you should outgrow a recurring cycle of doubt and re-assurance. What you want instead is a life of steady, unwavering assurance.

We gain assurance by imitating the faith of Abraham (Heb 6:12-13). To Abraham, God’s promise of blessing was utterly secure.

How did he know? Because God’s promises were backed up by a double testimony.

God can’t lie. Whatever He promises, He will do. Plus, when He speaks to Abraham, He adds an oath to confirm His promise.

Yahweh says, “Blessing, I will bless; multiplying, I will multiply you” (Heb 6:14; cf. Gen 22:17). Doubling the verb makes it an oath. God says, “I swear by Myself I will bless and multiply you” (Heb 6:16-18).

God is determined to fulfill His promises. He won’t change His mind. He will bless all nations through the seed of Abraham.

And, to make it personal: He will complete the work He’s begun in you (Phil 1:6). Believe this. Trust Him. He can’t lie, and He’s sworn to do it.