B.G 3.03

श्रीभगवानुवाच-
लोकेस्मिन् द्विविधा निष्ठा पुरा प्रोक्ता मयानघ। ज्ञानयोगेन साङ्ख्यानां कर्मयोगेन योगिनां ॥३॥

śrībhagavānuvāca-
lōkēsmin dvividhā niṣṭhā purā prōktā mayānagha। jñānayōgēna sāṅkhyānāṁ karmayōgēna yōgināṁ ॥3॥

The Lord said:
Oh sinless one, In this world, two types of 'niṣṭhā', i.e. sustained honest devotional paths, were prescribed by Me previously. The Yōga of knowledge for Sānkhyas, those who are predominantly knowledge oriented, and the Yōga of action for Yōgis, those who are predominantly action oriented.

Gīta Tātparya 3.03

'sāṅkhya' - Yōga that is predominantly knowledge oriented. 'yōga' - Yōga that is predominantly action oriented. 'niṣṭhā' is the determining factor for liberation.

The Yōga that is abundant in knowledge is Yōga of knowledge. The one which is abundant in action is the other.

"The Dēvas and the monks who are predominantly knowledge oriented and are called Sānkhyas. Within them, as Dēvas rely predominantly on knowledge alone, they are called "Primary-Sānkyas". Even though they are engaged in performing several actions involving miseries, they are to be understood as "Primary-Sānkyas" (mukhya-sānkyah). Others are Yōgis of action. Even the knowledgeable, when predominantly action oriented, become Yōgis of action. Certainly without these two (i.e. action and knowledge), no man attains the desirable human goals (purushartha). Perhaps, it is not possible for anyone to stay without action even for a moment. Action without knowledge cannot give the cherished human goals."

-thus states Brahmavaivarta

'niṣṭhā', i.e sustained honest devotion, is the determining factor for liberation.