It is true that nobody can prove fully that there is a God. But did you consider the possibilities?
Men of the
World say: “Show me and I shall believe”.
Yahweh our God loves the believe in His Name and in His deeds, His Works. Without
believe it is nearly impossible to please Him but to approach Him it shall be
those that believe, but not those who have blind Faith.
God wants to
communicate whit us, and with all that are open to learn about Him.
Jehovah God has given to everybody two witnesses to help us to see and to convince us of His existence. Because the knowledge of God may be seen in them who are looking, God having made it clear to them. (Ro 1:19) 
For in those who are willing to search and to believe in the One and Only God the work of the law shall be seen in their hearts, their sense of right and wrong giving witness to it, while their minds are at one time judging them and at another giving them approval;” (Ro 2:15) 
In human beings, both the spiritual dimension, which distinguishes them from animals with their instinct, and the ordered creation in the universe provide in the proofs for accepting an intelligent Creator.
Further there is the continuous handing down of those who saw the Force of God in working and who were able to tell about the miracles He did.
it is so that there is no scientific proof of there being One Godhead to be
laid in front of us.
Hebrew 11: 1-3, 5-6: 1 Faith  is the assured expectation of things hoped for, the evident demonstration of realities though not beheld. 2 For by means of this the men of old times had witness borne to them.
3 By faith we perceive that the systems of things were put in order by God’s word, so that what is beheld has come to be out of things that do not appear.
5 By faith Enoch was transferred so as not to see death, and he was nowhere to be found because God had transferred him; for before his transference he had the witness that he had pleased God well. 6 Moreover, without faith it is impossible to please [him] well, for he that approaches God must believe that he is and that he becomes the rewarder of those earnestly seeking him.
“Before the decree bring forth, [before] the day pass as the chaff, before the fierce anger of the LORD come upon you, before the day of the LORD’S anger come upon you. Seek ye the LORD, all ye meek of the earth, which have wrought his judgment; seek righteousness, seek meekness: it may be ye shall be hid in the day of the LORD’S anger.” (Zep 2:2-3 AV)
 “But without Faith [it is] impossible to please [him]: for he that cometh to God must believe that he is, and [that] he is a rewarder of them that diligently seek him.” (Heb 11:6 AV)
 “Because that which may be known of God is manifest in them; for God hath shewed [it] unto them.” (Ro 1:19 AV)
“Which shew the work of the law written in their hearts, their conscience also bearing witness, and [their] thoughts the mean while accusing or else excusing one another;)” (Ro 2:15 AV)
“And the apostles said unto the Lord, Increase our faith.” (Lu 17:5 AV)
“I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?” (Lu 18:8 AV)
“But that no man is justified by the law in the sight of God, [it is] evident: for, The just shall live by faith.” (Ga 3:11 AV)
God is One (video)