I strongly recomment the Holy Bible.
Other than that, I suggest:
bibleclassbooks.com/teaching-values/honesty.html
and
catholic.org/search/?q=books+about+sincerity
Here are some verses from the Bible that might help you:
Proverbs 6:16-20
There are six things the LORD hates, seven that are detestable to him: haughty eyes, a lying tongue, hands that shed innocent blood, a heart that devises wicked schemes, feet that are quick to rush into evil, a false witness who pours out lies and a man who stirs up dissension among brothers.
Micah 6:8
He has showed you, O man, what is good. And what does the LORD require of you? To act justly and to love mercy and to walk humbly with your God.
(Be truthful, honest, and sincere)
Zechariah 7:9
This is what the LORD Almighty says: Luke “Administer true justice; show mercy and compassion to one another.”
A Prayer for the Virtue of Honesty:
*Jesus, Prince of all Heavenly Truths, Your Words are carved for eternity! You have commanded the virtue of honesty. It is the power against all deceptions. Direct Your Spirit of honesty upon me, that my soul may always remain stainless. Guide my daily thoughts, words and actions, To join those living by the Spirit of Truth. For honesty yields harmony and loyalty, Enriching all human relationships. By the power of Your Spirit that flourishes, Honesty will prevail in this world! *
I also like the old-fashioned “Golden Rule” which says, **“Do unto others as you would have them do unto you.” ** You don’t like people lying to you, so don’t lie to them. You want people to be sincere with you, so be sincere with them.
There is no time at all in which dishonesty is acceptable to God. Loving and following God/Jesus requires constant and unwavering sincerity.
May God bless you with the answers you seek.
I hope this has helped you a little.
