How can one judge whether one is progressing on the spiritual path?

Guru Sahib says:

ਜਉ ਤਉ ਪ੍ਰੇਮ ਖੇਲਣ ਕਾ ਚਾਉ || ਸਿਰੁ ਧਰਿ ਤਲੀ ਗਲੀ ਮੇਰੀ ਆਉ ||
ਇਤੁ ਮਾਰਗਿ ਪੈਰੁ ਧਰੀਜੈ || ਸਿਰੁ ਦੀਜੈ ਕਾਣਿ ਨ ਕੀਜੈ ||੨੦||
“If you desire to play this game of love with Me, then step onto My Path with your head in hand. When you place your feet on this Path, give Me your head, and do not pay any attention to public opinion. ||20||”
(Ang 1412)

Rather than “progress” the question should be of “love” and commitment. In a relationship selfless effort without motivation of greed of gain or fear of loss, and unconditional love are required for a successful relationship.

Read Gurbani – communicate with the Guru and understand what Guru jee is saying.
Strive to implement the Guru’s teachings and the basic discipline outlined in Sikh Rehit Maryada in daily life. Live in the harmony and will of God and immerse yourself into God’s love and the love of the Saadh Sangat. This way anxiety and the question of “how do I check my spiritual progress does not arise”.
Man needs to do effort – the rest in God’s Grace. One must be patient just as a gardener has to be patient for the seeds of crops to sprout and grow. However, the gardener cannot expect the growth of the seed so quickly – it takes time. If the gardener is impatient and stops watering the seed then seed will die. One has to continue watering and caring for the seed and creating the right conditions for growth, then when God showers his grace and the sunlight showers over the seed, the seed sprouts. Similarly a Gursikh’s Rehit (way of life/discipline) is keep the field of the mind strong and fertile for the seeds of Sikhi and Naam to sprout.
Do Ardaas, Simran and contemplate in Gurbani – in this you will find your true answers.