"Make every effort to add to your faith goodness and to goodness, knowledge...." II Peter 1:5
The knowledge that is required to strengthen your faith is a practical faith that arises out of a relationship with Christ.
To have this knowledge you need to begin with a head knowledge. But also you need a HEART knowledge.
Jesus prayed for that:

The Apostle Paul thought it is important:
II Corinthians 4:6 – “For God, who said, “Let light shine out of darkness,” made his light shine in our hearts to give us the light of the knowledge of God’s glory displayed in the face of Christ.”
Romans 5:5 – “And hope does not put us to shame, because God’s love has been poured out into our hearts through the Holy Spirit, who has been given to us.”
Peter had a heart knowledge of Jesus. I am sure he remembered fondly of the encounter he had with the resurrected Jesus on the shore of the Sea of Galilee. Jesus tenderly reassured him that He had forgiven Peter and that He stilled believed in him! That day Peter was restored and called back to ministry. It was after that day he had his greatest ministry because now he had not just a head knowledge of Christ but a heart knowledge as well!
THE GOAL OF HEART KNOWLEDGE IS TO KNOW THE HEART OF GOD!
You can’t know God well until you get your heart right! Is your heart right?
The knowledge you want to add to your faith is a HEAD knowledge and it is also a HEART knowledge but what you really need is a HOLY knowledge!
Peter knew about that, too!
I Peter 1:13-16 – “Therefore, with minds that are alert and fully sober, set your hope on the grace to be brought to you when Jesus Christ is revealed at his coming. As obedient children, do not conform to the evil desires you had when you lived in ignorance. But just as he who called you is holy, so be holy in all you do; for it is written: “Be holy, because I am holy.”
As he wrote these words to these early Christians I am sure he was fondly remembering that day in the upper room when the Holy Spirit fell upon him and the other 119 Christians who were there. He must have had a warm feeling as he recalled preaching under the anointing of the Spirit and how 3,000 responded to his words by accepting Christ!
It is good to have a HEAD knowledge of God. It is even better to possess a HEART knowledge of Him, but the fulfillment of those levels of knowledge only comes when you receive a HOLY knowledge!
Do you have that holy knowledge? Have you received the Holy Spirit? Is your will surrendered to His will so His Spirit can fill you?
THE GOAL OF A HOLY KNOWLEDGE IS TO KNOW THE HOLINESS OF GOD!