People sometimes ask what the last incarnation of God was. According to the ten main incarnations, it was Lord Buddha. Then people question what the next incarnation will be, to which the answer is Lord Kalki. So does that mean that there are no incarnations in between?
When you reflect on this you will understand that there is no time or occasion without an incarnation. God is omnipotent. This world is His incarnation.
Further, if you genuinely want to grow spiritually, you will understand that God incarnates for every individual. God is ready. He is waiting for you to call Him. When you truly have the desire to know Him, attain emancipation from the cycle of life and death, to spiritually grow and then you call out to Him, God incarnates for you. This incarnation is known as Sadguru.
God does not send a Sadguru. He comes into your life as a Sadguru. When King Pariksheet truly wanted the answers to his questions: What is the purpose of life? How can I be liberated from the cycle of life and death? Who am I? Who is God? He cried for help from within for someone to clear his ignorance and Shukdevji arrived. No one had summoned Shukdevji nor arranged particular dates to organise a Katha. It is the divine Supreme God that arrived in the form of Shukdevji.
God incarnates specially for you. You need to recognise this. This is why we say:
Gurur Bhramā, Gurur Vishnuḥ Gurur Devo Maheśvaraḥ
Guruḥ sākṣāt parabrahma, Tasmai Śri Gurave Namaḥ
Meaning: Guru is Brahma, Vishnu and Shiv. Guru is Supreme God or the Absolute Truth. With this knowledge, I offer my obeisance to the Guru.