God could if God wanted to but God does not want to so He doesn’t. God gave us a res=ason why He doesn’t and Baha’u’llah revealed that in His Writings.
“He Who is the Day Spring of Truth is, no doubt, fully capable of rescuing from such remoteness wayward souls and of causing them to draw nigh unto His court and attain His Presence. “If God had pleased He had surely made all men one people.” His purpose, however, is to enable the pure in spirit and the detached in heart to ascend, by virtue of their own innate powers, unto the shores of the Most Great Ocean, that thereby they who seek the Beauty of the All-Glorious may be distinguished and separated from the wayward and perverse. Thus hath it been ordained by the all-glorious and resplendent Pen…”
Gleanings From the Writings of Bahá’u’lláh, p. 71
It is logical that if God exists God does not want to provide that proof because if God is omnipotent God could easily provide that proof.
If God had pleased He had surely made all men one people, means that God could have made all people believers, but
if God has pleased, implies that God did not want to make all people into believers, and this verified by the fact that not all men are believers. Rather, God wants everyone to
search for Him and determine if He exists by using our own innate intelligence, and then use our free will to make the decision to believe. God also wants us to have faith and believe that He exists without absolute proof.