“Praise the Lord!
Praise the Lord from the heavens; praise him in the heights!
Praise him, all his angels; praise him, all his hosts!
Praise him, sun and moon, praise him, all you shining stars!”

Psalm 148:1-4 ESV
The cause of lots of weak faith that is seen in fear, lack of trust and other warnings to weak faith in God is wrong focus.
When we focus on us, accomplishment, problems, we grow ever weaker. When our focus turns to God and his greatness (who and what He is, not just what he has done – get the full picture) then fear fades, trust builds, and faith in God is strengthened.
This is exactly why investing much time in Scripture, reading widely, is SO important. A friend quoted Packer the other day, I adapt: do you spend more time in the Bible than on your phone? In the words of men, even so called “Christian” writing?
Read Scripture.
“Praise the Lord!
Praise the Lord from the heavens; praise him in the heights!
Praise him, all his angels; praise him, all his hosts!
Praise him, sun and moon, praise him, all you shining stars!”
Psalm 148:1-3
Glorify God!