I agree that God is faithful even when we are faithless. But I dont think this is teaching that God is responsible for our faith, or lackthereof. We see that Israel was faithless regularly in the OT. However, that did not undermine God’s faithfulness towards Israel and his plan to bring hope and salvation to the world. The faithless were still held responsible for their unbelief (see Hebrews 4-5 and 1 Cor. 10) and God’s plans of salvation did not mandate the salvation and security of individual Israelites. They were still held responsible for THEIR belief or faithlessness.
If the receiver of faith could do anything whatsoever to deserve or earn the gift, that person would have every right to boast (
Ephesians 2:9). But all such boasting is excluded (
Romans 3:27). God wants Christians to understand they have done nothing to earn faith, it’s only because of what Christ did on the cross that God gives anyone faith (
Ephesians 2:5,
16).