A famous verse from Holy Gita says;
The Lord Said: Those who, fixing their minds on Me, worship Me, ever steadfast and endowed with supreme faith, these are the best in Yoga in My opinion. (B.G. C. XII; V. 2)
Many Acharyas are written commentaries on this Verse in different ways.
According to my understanding, Lord Krishna is encouraging two paths to reach Supreme such as path of wisdom (Vedantic enquiry) & path of Devotion. Although Advaita Vedanta Sadhakas would not agree that the way of devotion does not lead to liberation or ultimate goal further they says knowledge of the self alone can give liberation. But, the God in every religion has indicated that the deep devotion to Lord leads to liberation. This conflict is to be understand properly for progressing in spiritual life.
The devotion to God is highly regarded in all the great Hindu Scriptures including Bhagavatam, Ramayanam, Mahabharatha & all other Puranas & ithihasas. We can find so many devotees who actually realized the ultimate truth through this path in those stories of Puranas.
Swami Ramdas a great Saint says;
“Behold God as all, and still be His child and servant. You are at once He and His child. God is His own devotee. He is a mystery, but a revealed mystery, revealed in love and joy.”
So, Devotion to God is a one of best way to progress in spiritual way. When a devotee is in love with his Lord, he can attain purity in mind (Chitta Shuddi) and this lead to understand & feel the presence of God in every moment of his/her life. Lord Krishna said in Gita that, the Path of Devotion is more loving to him compare to path of knowledge. A devotee is never experience the rajas & tamasik (anxious or cruel kind) of thoughts in his mind as long as he is dwelling on Lord (Sattvic state of mind). In all the scriptures are recommended that the Sattvic mind is essential for understanding any advanced scriptural meanings.
The power of Devotion is fulfilment and love. The God is Love it means a devotee experiencing God all the time when he is practising the pure devotion (Shuddha Bhakti). Further says, a true devotee is not necessary to go through any vedantic enquiry or scripturual readings & contemplation for attaining spiritual wisdom. Lord Krishna says in Gita, he will grant the final wisdom to the one who fixing their minds on Lord, worship Lord, ever steadfast and endowed with supreme faith. This is the promise Lord Krishna made and which gives a great support to genuine seekers of Lord.
“God is always kind and loving. He never forsakes those who depend upon Him.”
The way of knowledge is also a great path undoubtedly, but it is a hard path according to Lord Krishna. Harmony of paths is very helpful because situations in life sometimes shake the faith of humans on Lord. If a devotee has some wisdom from the scriptures then it helps in tough situations to withstand and relate to his life. The Law of Karma, Vedantic enquiry about the existence of Self are the very useful for us.
“The surrendering of the weak and faulty will of the individual to God’s will, for eliminating thereby the ego sense, is truly easier than the assertion of Divinity within you so that the individual will may be transformed into the Divine Will. In the first case, you have an Almighty hand to lift you up and guard you against any fall, whilst in the latter, since you depend on your own gradually developing will, there is always the danger of a fall.”