"Krishna Bhakti" simply means "Devotion to Lord Krishna". One who does such Bhakti or Devotion to the Lord is called a devotee. Lord Krishna is dear to his devotees & they too are dear to Lord Krishna. In such a devotion to Lord, devotees have a burning desire to meet Lord Krishna. Gopis of Vrindavan, including Sri Radharani were such devotees who fell in Love with Lord Krishna.
Sri Radharani was a Gopi who was most near to Lord Krishna’s heart. Sri Radha's devotion and dedication towards Lord Sri Krishna was complete that is the reason that she was most dear to Lord Krishna. Sri Radha was not married to Lord Krishna but still she was most dear to Him even more than His wives. It was because Sri Radha was always full of devotion towards the Lord & never thought of anyone besides Lord Krishna. In pictures Sri Radha is almost always depicted alongside Lord Krishna.
Similarly we too should have devotion or Bhakti towards Lord Krishna.
As per the Bhagwat Gita, devotion is the easiest method to know the truth about self knowledge / soul knowledge & get close to the God. God himself declares about the glory of devotion in Bhagwat Gita: Chapter Eighteen verse 65 & 66 which are here given below.
Bhagwat Gita: Chapter Eighteen verse 65:
"man-mana bhava mad-bhakto
mad-yaji mam namaskuru
mam evaishyasi satyam te
pratijane priyo ’si me" (Bhagwat Gita: Chapter Eighteen verse 65)
"Sri Krishna says to Arjuna: Always think of Me, become My devotee, worship Me and offer your homage unto Me. Thus you will come to Me without fail. I promise you this because you are My very dear friend."
Bhagwat Gita: Chapter Eighteen verse 66:
mam ekam saranam vraja
aham tvam sarva-papebhyo
mokshayisyami ma suchah" (Bhagwat Gita: Chapter Eighteen verse 66)
"Sri Krishna says to Arjuna: Abandon all varieties of religion and just surrender unto Me. I shall deliver you from all sinful reactions. Do not fear."
In the above verses of Bhagwat Gita, Lord Krishna is assuring Arjuna that He shall always be with him in all circumstances if he is always in devotion to Him. Same thing applies to every human being also. If a person remains devoted to Lord Krishna then Lord promises that He shall deliver that person of all the sins of the past & purify that person. By doing such loving service to the Lord, certainly that person shall be in the eyes of Lord & Lord shall always protect that person.
So let's be devoted to Lord Krishna always. Let's sing His Glories, read literature regarding Him & also do loving service to humanity (charity etc.) in His name. So lets have devotion to Lord Krishna. Remaining in Krishna consciousness is good for everyone. Krishna is one of the names of God and it means all-attractive. So Praise to such a Lord.
Jai Shri Krishna