Assalamualaikum, in your book 'Way of the spiritual muslim', there is a quote from Ibnul Jawzi no.52. I couldn't quite grasp what was the actual message and how to apply it,it was about the combining of opposites. I would be very grateful if there is a brief explanation about it.
Ibn al-Jawzi says:
I seek to reach the ultimate of what can be reached of turning knowledge into action, so that I aspire to the fear of God that Bishr had and the asceticism of Maʿrūf. Achieving these things, along with [what I do of] the reading of books, teaching people and mingling with them, is unlikely.
I also seek to be needless of people, and wish to have a better material status than them. But busying oneself with knowledge prevents acquiring wealth, and accepting the charity of others is against dignity and self-respect.
I aspire to have children, the same way I aspire to write books, so that both of these act as my successors after my death. And the seeking of children has nothing to do with the business of the heart which loves seclusion.
I also seek pleasure through women, although the lack of wealth prevents acquiring it, and if the pleasure is acquired, it reduces motivation [for seeking other worthy things]. I also seek what is good for my body of food and drink, so that it is used to gentle and indulgent treatment, but the lack of wealth prevents this.
And in all of these things is the combining of opposites.
Compare my condition to those whose ultimate goal is the worldly life. I do not like that the acquisition of anything of the worldly life should taint my faith in any way, and I do not like that it should affect my knowledge nor my deeds.
How anxious I am to perform qiyām [to stay up at night for worship before going to bed] and to achieve true fear of God, while also refreshing my knowledge, and busying the mind and heart with writing, and with acquiring food that is fit for the body!
How sorrowful I become when I miss the opportunity to speak with God in private due to the meeting and informing of people! How much the fear of God fades when one has to seek what a family cannot do without!
 Bishr al-Ḥāfī (Bishr the Barefoot, 767 – 750 CE), one of the most famous early ascetics in Islam.
 Maʿrūf al-Karkhī (died about 820 CE), one of the most important saints of early Sufism, he was a Christian who converted to Islam, likely of Persian origin.
Ibn al-Jawzi’s message is that a spiritual Muslim is caught between the demands of the worldly life and the demands of the spiritual life. The point is to try to balance them rather than ignoring either side. He clarifies this teaching in many of his other quotes. So the true spiritual life is about trying to balance these opposite demands of life: worldly demands and spiritual demands.
If the message is still unclear to you, please let me know and I will try to clarify it further inshaAllah.