Success in spiritual life lies not in being the Best, but doing the Best.
If a devotee follows the instructions of Sri Chaitanya Mahaprabhu, he lives in the company of the Lord. Wherever he lives, he converts that place into Vrindavana and Navadvipa. This means that materialism cannot touch him. This is the secret of success for one advancing in Kishna Consciousness.
If you please the lord that is "Success" even though you are not materially successful. However if you do not please the lord – that is "failure" even though you are materially successful.
Love of Godhead means that you surrender to God. You have to do what God says! God says that give up all religions. There are many so called religions. There is also dharma of body. We have got dharma towards our country, family and children but you will find that you will never be satisfied. What makes you satisfied? “samsiddhih-hari-tosanam”. If you can please Hari, Krishna, that is success.
Success of our activites is when we have absorption in God.