God does not need selfsacrificers who suffer for Him. It is not logical, because He gave the Book to facilitate our worldly life, to orient ourselves and to prosper. Then, how can He wish we would throw our lives for "Him"? If He asks for it, He will never ask it for Himself because Allah is not selfish! He asks it for a purpose in order to protect your family, nation, and faith! It's completely different than sacrificing ourselves.

Allah hath purchased of the believers their persons and their goods; for theirs (in return) is the garden (of Paradise): they fight in His cause, and slay and are slain: a promise binding on Him in truth, through the Law, the Gospel, and the Qur'an: and who is more faithful to his covenant than Allah. then rejoice in the bargain which ye have concluded: that is the achievement supreme. (Quran 9:111)

We offer our whole selves and our possessions to Allah, and Allah gives us Salvation. This is the true doctrine of redemption: and we are taught that this is the doctrine not only of the Quran but of the earlier Revelations, -the original Law of Moses and the original Gospel of Jesus. Any other view of redemption is rejected by Islam, especially that of corrupted Christianity, which thinks that some other person suffered for our sins and we are redeemed by his blood. It is our self-surrender that counts, not other people's merits. Our complete self-surrender may include fighting for the cause, both spiritual and physical. As regards actual fighting with the sword there has been some difference in theological theories at different times. In the New Testament St. Paul, in commending the worthy fruits of Faith, mentions Gideon. Barak, and other warriors of the Old Testament as his ideals, "Who through faith subdued kingdoms... waxed valiant in fight, turned to flight the armies of the aliens..." (Hebrews, 11:32-34).

And if you take the burden and sacrifice (not purposeless sacrificing yourself!), you have the right for the worldly and afterlife reward. But you can see clearly that the worldly prosperity is not sin but reward! And if that is the case, then it makes no sense to throw lives aimlessly. It's not logical! For Allah says this:

And there are men who say: "Our Lord! Give us good in this world and good in the Hereafter, and defend us from the torment of the Fire!" (Quran 2:201)

To these will be allotted what they have earned; and Allah is quick in account. (Quran 2:202)

Question: How do I know God?
Answer: How can someone know you? God can be comprehended and known the same way like you!
You have to talk to Him. You are also waiting for someone to notice you, to recognize your abilities, to praise you. Or aren't you looking for a deep relationship where you can put yourself in full intensity? To do so, you can legitimately expect others to do the same. God works the same way. If you do not devote yourself, do not expect Him to make you feel His care. However, beware! "Devotion" should not be instigated and manipulated by an outside person, because it can go far beyond the purpose of Allah! Many nations have been exterminated in the name of the sacred devotion. Satan attacks on the holiest sites.
You have to give, in order to get. If you desire love, give love to others and love will flow to you. If you live in poverty, try to donate even so and a kind of wealth will greet you back that money can never do.
If something is true, it is not true only within a group of people. Gravity does not work in a way that it affects me while it does not affect you. If you can give, love, open outward, the outside world will open towards you. This is the real wealth!