Is it okay to lie to people? Can Satan answer me this?
by speaking falsehood you will achieve nothing, other than becoming spiritually weaker. The ancient texts are clear that speaking the truth and living according to it leads over time and with proper practices to manifest thoughts more in material reality. This has been explained in the yoga sutras: "When one is firmly established in truth (Satya), actions and their fruits become dependent on the will of the practitioner." This phrase indicates that one who consistently and authentically practices truth gains such spiritual power that his words and actions align with reality, bringing results consistent with his intentions. In other words, the words of a person rooted in Satya acquire creative power, manifesting what is said.
“Only through truth can the path of the gods be traveled: Truth alone triumphs, not falsehood; by truth, the path of the Gods (Devas) can be traveled, it is the path on which the seers walked, having nothing to desire where that is: the highest treasure attained by truth" (Mundaka upanisad, verse 3.1.6)
Other ancient texts speak about untrutfulness:
Atharvaveda (4.39.7):” Falsehood is darkness, the universe is immersed in darkness where there is no truth.”
Wherever possible, it is necessary to live in accordance with truth, also you are not forced to tell everything about yourself to others, many things must be kept secret. In this sense, falsehood can only be used in cases where you need to protect yourself or cases according to your common sense.