Bhagavad Gita Chapter 18, Verse 65

मन्मना भव मद्भक्तो मद्याजी मां नमस्कुरु | मामेवैष्यसि सत्यं ते प्रतिजाने प्रियोऽसि मे ||

manmanā bhava madbhakto madyājī māṁ namaskuru mām evaiṣyasi satyaṁ te pratijāne priyo 'si me

Be with your mind fixed on Me, be devoted to Me, worship Me, and offer obeisance to Me. You will come to Me alone. Truly do I promise you, for you are dear to Me.

Krishna gives the most secret instruction. 'Manmanā bhava madbhakto madyājī māṁ namaskuru'—be (bhava) with your mind fixed on Me (mat-manā), be devoted to Me (mat-bhaktaḥ), worship Me (mat-yājī), and offer obeisance (namaskuru) to Me (mām). 'Mām evaiṣyasi satyaṁ te pratijāne priyo 'si me'—you will come (eṣyasi) to Me alone (mām eva). Truly (satyam) do I promise (pratijāne) you (te), for you are dear (priyaḥ asi) to Me (me). This is the most secret instruction: fix your mind on Krishna, be devoted to Him, worship Him, and offer obeisance to Him. If you do this, you will come to Him alone. Krishna makes a promise: this is the truth, and you are dear to Him. This is the direct path to union with the Supreme.