Vitthara Sutta: Five Strengths
In this sutta, the Buddha teaches five strengths to be developed and maintained that directly support integration of the Eightfold Path. The first, strength of conviction, immediately differentiates the Buddha’s Dhamma from faith-based religions. Conviction places initial motivation towards developing the Dhamma on the knowledge that a human being has awakened, gained full human maturity, and teaches other’s to do the same. Nothing needs to be or should be, taken on faith. 
The second quality, conscience, speaks directly to the initial condition of ignorance of Four Noble Truths – wrong thinking. As thinking develops from wrong view to Right View it is mindfulness of personal behavior that reveals ignorance and also reveals the practical development of the Dhamma.
As one develops understanding of their own individual stress and suffering caused by ignorance of Four Noble Truths, authentic concern and compassion for others naturally arises.
The persistence the Buddha is referring to in this sutta gains its strength from the initial conviction in the Buddha and his Dhamma. Knowing the efficacy and immediacy of the Dhamma, persistence is developed and maintained.
The fifth strength the Buddha teaches is insight. Often translated as “discernment,” insight is the more appropriate word as it is insight into Three Marks of Existence  that recognition and abandonment of views rooted in ignorance of Four Noble Truths are developed. 
These five strengths show the practical qualities to hold in mind, to be mindful of, to become free of ignorance of Four Noble Truths, and to become Rightly Self-Awakened.
My comments below in italics.
Anguttara Nikaya 5.2
The Buddha addressed those gathered: “Friends, there are five strengths needed for developing the Dhamma:
“One who is developing the Dhamma has conviction through understanding. They understand that the Buddha is Rightly Self-Awakened. They understand that the Buddha, consummate in knowledge and conduct, is an expert with regard to the conditions of the world. They understand that the Buddha is unsurpassed as a teacher to those fit to be taught. This one has strength of conviction.
“One who is developing the Dhamma has a strong conscience. They feel shame at engaging in bodily misconduct, or verbal misconduct, or mental misconduct. (Conscience is framed by the moral and ethical factors of the Eightfold Path – Right Speech, Right Action, and Right Livelihood)
“One who is developing the Dhamma has strong concern for the suffering of others for their bodily misconduct, or verbal misconduct, or mental misconduct.
“One who is developing the Dhamma has developed strong persistence for recognizing and abandoning unskillful mental qualities and for developing and maintaining skillful mental qualities. They are steadfast and resolute with regard to skillful mental qualities. (Steadfast and resolute supported by the framework of the Eightfold Path)
“One who is developing the Dhamma has strong insight into Three Marks of Existence that leads directly to the cessation of stress and suffering. 
“Friends, these are the five strengths of one who is developing the Dhamma. So, train yourselves:
• I will develop and maintain the strength of conviction.
• I will develop and maintain the strength of conscience
• I will develop and maintain the strength of concern
• I will develop and maintain the strength of persistence
• I will develop and maintain the strength of insight.
“This is how you should train yourselves.”
End of Sutta