I don't doubt the sincerity of your aunt and uncle's faith, nor do I doubt their sincere concern for those in their family who don't know Christ. They don't want you to spend eternity separated from God (and from them); they want you to know God's peace and have the hope of heaven in your hearts.
But I'm sorry they don't know how to express their concern for you in the way they should. When Jesus walked this earth, people were attracted to Him and were delighted to be in His presence. Shouldn't this be true of His followers also? Of course. Jesus said, "By this all men will know that you are my disciples, if you love one another" (John 13:35).
Even little children flocked around Jesus - so much so that His disciples tried to keep them away. But the Bible says, "When Jesus saw this, he was indignant. He said to them, 'Let the little children come to me, and do not hinder them'" (Mark 10:14). Sometimes, I'm afraid, we are like those disciples, and we end up keeping people away from Jesus. But He welcomes them - and He wants to welcome you.
Don't let your aunt and uncle's imperfections keep you from Christ. God loves you, and you need His forgiveness and hope. By faith ask Christ to come into your life today - and He will.